Angevin Empire 900–1,000 Including: The siege of Wexford took place in early May 1169 and was the first major clash of the Anglo-Norman invasion of Ireland.

The town was besieged by a combined force of Normans under Robert Fitz-Stephen and soldiers loyal to Diarmait mac Murchadha.

Those who agreed to help included Richard de Clare (nicknamed "Strongbow") and half-brothers Robert Fitz-Stephen and Maurice FitzGerald.

The 1971 Capuchin Annual (page 399) argues that this skirmish "deserves greater respect in history than it has got" because it was "the first battle of the Norman invasion, the first attempt to stop the foreigners, the first bloody encounter in a struggle which was to endure for eight hundred years".

Wexford had got news of the approaching army and prepared to fight the invaders on open ground outside the town.

After about three weeks of inactivity, Diarmait and Fitz-Stephen's forces attacked the territory of Osraighe (anglicized Ossory) on Leinster's western border.

High King Ruaidhrí Ua Conchobhair marched his forces into Leinster and, with the mediation of the Church, the commanders of the two armies began negotiations at Ferns.