874 The great danish army split up

 
England
The great danish army was split up in 2 parts. Halfdan took his army and went to Northumbria where he was recognized as a king. In the Scottish borderlands Halfdan had to fight against 2  tribes the Picts and the Gaels. The second part of the viking army was under command of Gudrum, Oscytel and Anwynd and that army went southeast and made a winter camp in Cambridge.

King Burgred fled
Danish vikings in Mercia forced the king Burgred to resign and installed Ceodwulf, whom they later sacked and took complete control of the Angles area.
Tamworth was sacked. King Burgred fled and eventually ended up in Rome, where he stayed until he died. Tamworth remained a ruin until 913
Iceland
Norwegian vikings had started to immigrate to Iceland. And Ingolfur Arnarson founded Reyjkavik.
Ireland
Went into the "forty years rest" period from 874-914
Scotland
Amlaíb Conung, King of Dublin, was killed in Scotland on a campaign against Causantín mac Cináeda.