According to the Anglo-Saxon Chronicle, a raid by Gruffudd ap Llywelyn on Leominster in 1052 resulted in the Battle of Llanllieni, between the Welsh and a combined force of Norman mercenaries and English Saxon. The Welsh won.
Source: Gwynfor Evans (1974). Land of My Fathers: 2000 Years of Welsh History. Y Lolfa. page 156. ISBN 9780862432652