Eosa (also called Ossa) is a relative amd companion of Oisc, son of Hengist. He first appears in Geoffrey of Monmouth's Historia Regum Britanniae to be in charge of the garrison at York when Oisc flees there. He is later Oisc’s partner in rebellion, replacing Ebissa in that role.
Wace and Lawman make no mention of Eosa’s position at York. Instead, at this point, Wace brings in Ebissa as still Oisc’s companion.
Geoffrey, Wace and Lawman all make Eosa to be Oisc’s companion in his final rebellion. Lawman also introduces Ebissa in this and calls Eosa Ossa the other, creating a triad of leaders.
==Some Name Variations==
LATIN: Eosa; FRENCH: Ossa; ENGLISH: Ossa.