856 - Vikings plunder France

From Jeufosse by the Seine river  Bjorn Ironside and his vikings ruled with fire and sword, Orleans(18 april), Paris(Burned 28 December) and  and Rouen was attacked and the Eure area was plundered. Later the vikings received fresh reinforcements probably from England.
Vikings established a fortified camp in the island Oscellus (Oissel or Jeufosse) for six years.
Charles the bald gave Maine to Erispoe, duke of Brittany in return for an alliance against Vikings
Olaf the white became the second king of Dublin, he ruled until 871
Thors Hammers from runestones
Considering the time needed to collect a large ransom and the distance of Pamplona from the coast, we can assume that the Vikings must have been in northern Spain for much of the summer of 858. 

855 - Bjorn Ironside arrived in France

Claus Deleuran: Viking retreat
A Viking army sailed up the Seine to Pîtres (18 July). He was joined on August 17 by Bjorn Ironside. They looted the Perche region before the Loire Vikings were attacked by a Viking chieftain called Sigtrygg (Sidroc). Sigtrygg had been operating around the Seine and in Ireland, and had in the past sailed with Gudrød. He was now allied with Erispoë, who had paid him to get rid of Hallstein, Gudrød and Åsgeir And defeated them at Saltus articus
The viking army, which had suffered heavy losses in the Loire area, where only 300 vikings survived made a winter camp at a French island in the river, named Jeufosse.
Orkney Islands
Ketil Flatnose attacks the restt of the Pictish kingdom of Dalriada
Orm, Viking raider
Cerball mac Dunlainge slaughtered a bunch of Viking intruders, led by Rodolb. In the aftermath of the battle Cerball mac Dunlainge was captured by Vikings, but he escaped.

Cerball joined a group of Danes led by a chief named Orm in their war with the Norwegians. These Danes might have come from Waterford. People of  Munster begged for Cerball's help against the Vikings, and Cerball with local Irish from Osraige & Munster  And Orm's Danish vikings inflicted a heavy defeat on the Norwegians.
Dubh-Ghenti led by a Norse-Irish chieftain named Orm attacked Gwynedd, only to be repelled by Rhodri Mawr who killed Orm.

854 - King Horik was killed

C.Deleuran Horik 2 (Erik Barn) king of Denmark 854
Rorik and Godfrid Haraldsson was some of king Horik`s relatives, they returned from a viking raid in Frisia, their intention was to throw Horik of the throne, and under the violent battles - King Horik and most of the Danish royal family was killed. Rorik and Godfrid were defeated an fled to Frisia. A young boy became the new king his name was Horik 2 or Erik Barn.
The Earl of Hedeby banned Church bell ringing
Earl Howi took action against the church in Hedeby, he chased the Christian priest away and stopped all church activity. The new young king Horik 2(Erik barn) would like to maintain the good relationship with Ansgar and earl Howi was therefore sacked and the church was reopened and could also ring the church bells. Horik 2 showed more goodwill so a church was built in Ribe.
Ribe loot 800 AD
The Viking chieftain Ubbe set up a base camp at Milford Haven with 23 ships. A new overwintering camp was set up on the Isle of Sheppey,  Kent
Vikings sacked Blois but were repulsed at Chartres and Orleans by  an army led by bishop Agius.
Lothar and Charles the Bald agreed to take measures to secure the coasts against viking raids.
A fleet of Danish ships attempted gather the tribute from Grobina(Seeburg), but was defeated.
Olof  of Sweden raised an army and tried to capture the former viking colony, in the process vikings destroyed a place that Rimbert called Seeburg, Grobina. The town had 7,000 armed men to protect it, but the town was pillaged, and burnt by the Swedes.
Orkney Islands
Ketil Flatnose continued his conquest of the Pictish kingdom of Dalriada.
Viking raider
Muslims captured 2 viking ships at the coast outside Portugal.
Welsh Annals recorded that Vikings were referred to as Y Llu Du attacked Môn.

853 Vikings Tour de France

Noerre Naeraa runestone 850-875 found at Naeraa church
Inscription "Thormund enjoy the hill"
May: Hastein destroyed Lucon.
July: Viking raiders in France sailed from Nantes to the Tours area. A raid was made on The monastery at Saint-Florent-le-Vieil
8 November:The monastery Marmoutier were plundered.
People began to immigrate from France, because of the instability and devastation and French rural residents destroyed roads and destroyed bridges to prevent Vikings entering their area.
Olaf the White (Amlaibh) proclaimed himself king of all Norwegians in Ireland . The Irish king Mael Seachlinn tried effortless to unite the Irish.
Younger rune alphabet introduced ca 800 AD
Orkney Islands
Kjetil Flatnose a Norwegian adventurous viking ruled Hebrides and the Isle of Man, included parts of Skye, Mull and Islay. All these had been part of the Pictish kingdom of Dalriada, until Kjetil defeated the last Picts. The Picts, was called the painted ones, because they covered their bodies with blue paint in intricate patterns.

852 - Vikings left the Seine area

Viking Dragon ship the Bayeux tapestry
Rorics brothers son Godfred made winter camp in the Seine area with a viking army, but was convinced to leave after he received a huge sum of money from the Franks.
Ansgar went on a second christian mission to Birka, Sweden, with recommendations from king Horik and king Louis the German, the Swedish king Olaf treated him friendly.
9th century Viking raiders fighting
160 Norwegian ships returned to Ireland to fight with Danes in a sea-battle and Ragnall became the first king of Dublin, he ruled 4 years. A viking camp was established at Carlingford Lough (county of Louth). Armagh was destroyed by vikings.

851 - Battle of Aclea

Vikings plundered London and Canterbury.
350 Viking ships came into the Thames and stormed Canterbury and London and put to flight Beorhtwulf, King of Mercia with his army, and then went south over the Thames to Surrey and King Aethelwulf and his son Aethelbald with the West Saxon army fought against them at Oak Field Aclea, and there made the greatest slaughter of a heathen raiding-army that we have heard tell of up to the present day, and there took the victory.
"The Anglo-Saxon Chronicle"

One of the few victories for the West Saxons in Wessex, which made the viking raids decrease for 14 years. The exact location of the Battle of Aclea has never been identified. Although the Old English Aclea could be the modern Oakley there a number of settlements with the same name. Suggested locations include the Oakley that lies some four miles to the north west of Bedford on the Great Ouse and the village of Water Oakley in Berkshire.
Linguistic evidence of Scandinavian settlement in England
Battle of Dundalk bay Danes captured Dublin from the Norwegians.
Annales Bertiniani tells of viking pillaging in Frisia

850 London and Cantebury was sacked

Peter Nicolai Arbo
Low countries:
In Friesland Harald Klak died and his brother Rurik became ruler. Rurik ruled Friesland, Dorestad and the Rhine area. While Harald Klak had defended the area, the situation changed. Rurik used Friesland as a base where future viking raids took place. Rurik captured Utrecht and kept the town for 70 year
Rurik sent 350 ships to England. The attackers captured the island Thanet, Kent and pillaged and looted the surrounding area. London and Canterbury was stormed and plundered. Vikings wintered for the first time in England. The first overwintering was on the Isle of Thanet in Kent
The king of  North Brega launched a rebellion against the Irish high king and he was supported by a band of vikings. The Danes defeated the Norwegians in a battle at Carlingford.
Island of Man 
The island of Man was settled by vikings.
Welsh Annals told that Cyngen died on the swords of "the Heathen," supposedly meaning viking raiders. The southern Welsh districts of Gwent, Glamorgan and Dyfedd was raided several times for twenty years by vikings.
The Frankish empire also had viking raids as the war between the sons of Louis the pious continued.
Ansgar created the first church in Hedeby and a second in Ribe. The church was build of wood on specific areas given by king Horik. Earl Howi and the citizens of Hedeby complained about the church bells and ringing church bells became forbidden.
Odense, Denmark
During archaeological excavations of the Viking castle at Nonnebakken, Odense led by Mads Runge, in 2015 a special item was found: a Viking Valkyrie riding a horse Jewelry dated to 850 AD
Viking Valkyrie riding a horse Jewelry(© Odense Bys Museer)

849 - Ansgar became Archbishop

Louis the German gave Ansgar the archbishopric Hamburg-Bremen, After the split up of the Frankish empire Ansgar had financial troubles, but now he had the goodwill of both the Danish king Horik and Louis the German, Horik granted Ansgar the right to preach the christian faith in Denmark.
The monastery of Iona decided to remove Columba's relics and the monastery was abandoned , because of excessive viking raids. The Irish king Malachai and his champion Tighernach, lord of Loch Gabar, attacked and captured the Norse stronghold of Dublin.
Alfred the Great, King of the Anglo-Saxons was born

848 - Bordeaux was plundered

Internal opposition and turmoil convinced Horik to seek peace and secure the border.
The Franks split into 3 kingdoms. In the Summer  Bordeaux was plundered by Viking raiders. King Charles the Bald sent a Frankish fleet to end the siege. Despite they destroyed Viking ships on the River Dordogne they fail to save the town. The Abbey of Saint-Pierre in Brantôme was looted.

Louis the German, ruler of East France was seeking peace, Ansgar acted as a middleman when the 2 kings negotiated and he won the respect of king Horik and king Louis the German.

According to the Orkneyinga saga Rognvald  "The Wise" Eysteinsson was the first viking who ruled Orkney.

The arrival of a fleet with large number of Scandinavian warriors, these were different from the first raiders, that the historians named them "dark heathens of black foreigners, they were probably Danish, they overwhelmed the Finngall "fair foreigners" who came from SW Norway and attacked their base at Dublin, and they plundered and killed many men.

According to Irish sources Thorir was the heir of a king of "Viking Scotland" who took an army to Ireland in 848 and founded a camp at Cork.
Máel Sechnaill mac Maíl Ruanaid, High King of Mide, defeated a Viking army at Sciath Nechtain.
Vikings were defeated at Sligo, Kildare, Cashel and Cork

847 Vikings was bribed to leave Brittany

BrittanyA group of Danish Vikings landed in Brittany and started plundering in the Breton March. Duke Nominoe of Brittany failed to defeat them in battle, but manage to bribe with gifts and persuaded the Vikings to sail away (approximate date)
Agonn (Haakon) and his viking raiders were looting in Ireland.

846 The later duke of Normandy Rollo was born

A stamp from Jersey showing Rollo
The later duke of Normandy Rollo was born, he was also known under the name Ganger-Hrólf because he was to big to ride a horse, when he received the Duchy of Normandy he took the name Robert and converted to Christianity. More info here: http://www.normandescendants.org/historical-truth-rollo/

845 - Vikings attacked Hamburg and Paris

Northern Germany
King Horik attacked Hamburg with 600 ships. Ansgar had to run quickly out of the burning town, where church, monastery and library was destroyed. Horik later released all Christian prisoners and returned some of the stolen goods.

Bishop Gautbert was chased out of the Swedish town Birka, by an angry heathen mob, who did not appreciate his preaching of the Christian faith.

A group of vikings returned from Spain to the Loire river in march 845. And on the 28th march chieftain Ragnar Lothbrok sailed up the Loire and hung 111 prisoners then attacked Paris, which Castle Cite was conquered, Charles the bald had to pay 7000 pounds of silver in a huge Danegeld to sail away. Ragnar Lothbrok got his name from animal skin trousers he wore while fighting a poison-breathing serpent (the Lindorm). Ragnar had many sons, including Ivar the Boneless, Halfdan White-shirt, Björn Iron-sides, and Sigurd Snake-in-the-eye.
Bordeaux was attacked in autumn.
Count Kobbo of Sachen, a visitor to king Horiks court, wrote that Reginarius(Ragnar Lothbrok) visited Horik and bragged about his raids and showed the gold he had received from Charles the bald.Ragnar Lothbrok had received a disease when he was in the foreign lands, and he died 3 days later. King Horik then killed all the surviving members of Ragnar Lothbrok`s raiding expeditions.
Ragnar Lothbrok and the 2 females in his life

Ansgar mentioned that Ragnar Lothbrok had received Turholt monastery as a gift from Charles the bald. Horik promised the Franks that the raids would stop, but Frisia was attacked the year after.

Ireland, Annals of Ulster : King Malachai from Meath Ui Naill managed to capture viking chieftain Turgesius(Turgeis, Tuirgeis, Turges, and Thorgest), and had the viking king of Dublin drowned in Loch Owel.

Forannan, the abbot of Armagh, was captured in Munster.
Vikings won a victory at Dunamase.
Vikings founded a camp at Cluain Andobair (Co Offaly) and at Limerick.
a small group of Vikings was left behind stranded on Menor Island, they converted to Islam and settled on the island as dairy and cheese makers. The aided the local emir with advice about shipbuilding and that they served as oarsmen when the emir built a fleet to defend Seville and Córdoba against future Viking attacks.

844 - Vikings attacked Spain

A viking fleet of 70-80 ships plundered up the Garonne river and attacked Toulouse and then sailed to Spain and attacked the Asturians and Gijón, on the coast of Asturias, was the first place they made landfall and they later attacked Muslim provinces in Spain.
On the 31 July they were defeated by the christian Asturians in the province of Galicia near Oviedo, they moved on to attack La Coruna, but was defeated and lost 60-70 ships but their luck turned and outside the coast of Lisbon viking axes and Arab sword battled for the first time in history. Lisbon was sacked on the 20th August 844 and Seville was sacked 3rd October 844, Cadiz, Medina, Sidonia, Niebla, Beja and Algarve was also plundered. This was written in Annales Bertiniani, one of whose authors was the Spanish Prudencio, the Bishop of Troyes and also written in the Crónica Albedense.
King Raedwulf of Northumbria was killed by vikings.
Toulouse was attacked by vikings.
Dorestad was raided by the Vikings.
The trollstone also known as the magic stone, and is placed at Sjellebro Kro. It only bears a trollmask and no runes. It was placed by a ford, and should scare evil forces away from the ford.
The Annales Bertiniani,tells us that the Breton duke Nominoe was in war with vikings.
Turgesius raided holy places in Ireland.
Vikings build camp at Lough Ree(County Longford/Roscommon/Westmeath)

843 - Vikings attacked Nantes

Viking ships on the Bayeux tapestry
A viking fleet of 67 ships sailed up Loire and created a terrible bloodbath in Nantes, where a huge crowd was gathered for St. Johns day.
The Frankish empire was split up in 3 parts and vikings established their first raiding base in France at Noirmoutier.
Hastein was mentioned for the first time, he was a son of Ragnar Lothbrok.
Prudence of Troyes began writing on Annales Bertiniani
Friesland was under control by Danes from 843-885.

842 - Vikings gained a stronghold in Dublin

The first recorded Irish-Viking alliance according to the Irish chronicles, camps were build at Lough Swilly(Donegal), Rosnaree(Meath) and Cael Uisce(Uncertain).
A viking fleet destroyed Quentovic(South of Bourgogne) they killed and captured everybody and left nothing, except for the building the owners bought free.

Hustyn Chronicle tells that Askold and Dir ruled the Rus, they were Swedish nobles or descendants of Swedes.

841 - Rouen, Nantes, Bordeaux, Quentovic was plundered

At Fontenay, the sons of Louis the pious clashed in a bloody battle, where the core of the Frankish military power was destroyed. The Frankish empire was now vulnerable and ready for some serious looting. All coastal areas from the Elbe to Garonne was plundered. Rouen, Nantes, Bordeaux, Quentovic was plundered and burned. A frightening fear had found it place to the western European population, and nowhere when the vikings arrived they met any serious resistance.
At St-Wandrille 26 Lbs silver was paid for the release of 68 captives and also 6 lbs were paid for the monastery
Lothar called for help from his Danish vassal in Rustringen, the former Danish King Harald Klak who was given the important island Walcheren with the start of Schelde and orders to defend the coast.

Ealdorman Herebyrth was killed by vikings at the Romney marsh and raiding in Lindsey,Kent and East Anglia.Aethelwulf of Wessex attacked the vikings at Carhampton, but was defeated.
Norwegian vikings began a winter raid on England and London and Rochester was attacked.
Dublin, Ireland was founded by Norwegian vikings as a viking stronghold. And settlements and a fort were also existing at Linn Duchaill Lough Neagh(County Antrim/Armagh/Derry/Tyrone) and Linns near Annagasson (Louth)

840 - Viking raids continued

French viking winter camps
Louis the pious died, and his sons Charles the bald, Lothar and Louis the German fought intense to gain their fathers throne. The brother war created a new wave of intense lucrative viking raids.
Ealdorman Wulfheard defeated a viking fleet of 33 ships at Southampton. Aethelhem attacked the same navy at Portland, but his army was defeated and he was killed. Portland was raided.
Norwegian Vikings made a winter raided in England.
Viking raids on Great Britain 840-860

More and more vikings arrived in Ireland.

839 - Vikings expanded Picts were defeated

Frisia was attacked by a viking fleet
Vikings stayed for the winter 839-40 in Ireland after a series of great victories against the Irish. They mad a camp at Lough Neagh which they occupied for 3 years. Vikings overwintered for the first time in the newly established longphort in Dublin.
Vikings also defeated the Picts in their own kingdom. In a major battlet the Ulster chronicle tells us that, the Vikings killed most all of the Pictish nobles and the king of Picts Eogann mac Oengusa and Áed mac Boanta the king of the Scottish kingdom Dál Riata.The Picts in Scotland never recovered and the possibility of a counter-invasion disappeared.

In 839 Swedish vikings reached Miklagaard (Istanbul), they did not manage to sack the city.

838 - Horik demanded Friesland

Early Frankish shield
A viking fleet was destroyed by a storm and an emissary from King Horik demanded that Louis the pious should give up Frisia and Wagria, but Louis the pious denied Horik`s demands, he was not that weak yet all though the Vikings had a victory in 837 near Walcheren.
The Anglo-Saxon Chronicle records that, a “great ship-horde came to Cornwall" and at the Battle of Hingston Down, Egbert of the West Saxons defeated the Danish and their West Welsh allies from Cornwall. It was the first time that Vikings had been recruited as mercenaries to help a Celtic people in Britain.

In 825, Egbert had established his kingdom as the strongest kingdom in Britain, he had crushed the Mercians at a place called Ellendun,outside Swindon. In 815, Egbert raided Cornwall “from east to west”. So the Cornish wanted revenge, but they were unsuccessful.

837 - 60 Dragon ships on the Liffey

The Irish church annals reported of a fleet of sixty long ships on the Liffey carrying 1.500 men, it was led by Saxolb (Soxulfr). The vikings build a fortress at Dublin(Ath-Cleath) in the following years Viking activity kept increasing in Ireland.
Frisia was attacked again and on the island Walcheren vikings killed some of the emperors men and robbed more and when they left they demanded taxes and they returned to Dorestad where they also demanded tax. The emperor was on a journey to Rome, but returned as quickly as possible to Nijmegen, only to find out that the vikings were gone, Louis the pious investigated the raids and he found out that the local Frisian leaders were weak or cooperating with the viking raiders. The emperor sent pious abbots and vigilant counts to Frisia.

Viking naval warfare
The Vikings followed their kings or leading aristocrats, and the soldiers was referred to as a hird, or huscarls. The king or jarl (earl) would call out his men for campaign, and the standard period of duty was four months per year. Mercenaries were also employed, and often the Danegeld was collected to pay them, with the rest of the plunder going to the regular soldiers

The smallest unit in the army was the ship’s crew, and the smallest ship allowed was 26 oars. Most ships tended to number between 32 and 50 oars, though the largest ships were probably used for transport nearer home rather than sea journeys. The ship carried the necessary number of soldier/oarsmen and additional troops up to twice that number, although one ship is recorded to have carried 574 men.

The fleets could be just a few ships, depending on the target, but fleets in the scores or hundreds were much more common

836 - Dorestad was plundered 3rd time

Vikings decided for their 3rd annual raiding party at Dorestad.
The Anglo-Saxon Chronicle told us that In Somerset, England, Egbert was defeated in 836 at Carhampton by 35 Danish viking ships.
A large group of probably Norwegian originated vikings attacked the Earn valley & Tay valley area in the Pictish kingdom.
Worms, Germany
King Horik of Denmark sent his royal emissaries to the emperors court where he told the emperor that he was against the raids on Dorestad. Horik also complained that some of his emissaries were killed at Cologne, the emperor agreed to pay a purse full of coins. After the emperors yearly autumn hunting expedition new emissaries arrived meeting with a message from king Horik, that he had arrested and killed some of the responsible from the Dorestad raids, Horik then demanded more money.
The Irish medieval tale "The War of the Irish with the Foreigners" tells us that the viking leader Turgesius (Nordic Thorgísl) forced Christians in Ireland, to participate in heathen religious practices with animal sacrifices under the firm leadership of his wife the völva Ota in the Clonmacnoise cathedral.
Irish Chronicles reported of a viking camp built at Arklow in the county Wicklow
Christians forced to participate in heathen rituals

835 - Dorestad plundered again

The island of Sheppey, South East England was raided.
Vikings attacked the Frisian town Dorestad for the second time.
When the emperor Louis 1 the Pious arrived to Aachen, from a meeting in Lyon and heard about the attack he reinforced the coastal guard and then went on his yearly autumn hunting in the Ardennes forest.
The first construction of Viking Longphorts began.
The West Welsh(Cornwall) were forming an alliance with the Viking raiders whom they allied with to fight against the Anglo-Saxon King Egbert of Wessex whom had defeated the Cornish at Gafulford in 823

834 - The Viking ship of Oseberg was buried

The Vikings raid the rich Frisian trading town Dorestad, some of the townspeople were killed others were taken prisoners and part of the town was burned.
The Viking ship from Oseberg was buried in a mound in 834, but parts of the ship date from around 800.
There were found animal bones from fourteen or fifteen horses, and a cat among the ship. The rest of the Oseberg ship can now be found at a museum.
The Oseberg ship at Kristiansfjord

Aud den djuptenkte, one of the first settlers on Iceland was born.
Treasure chest found at The Oseberg ship
Oseberg  ship was 21 m long 30 oars

The Oseberg ship at The Viking Ship Museum