Corpus of Electronic Texts Edition
The Flight of the Earls (Author: Tadhg Ó Cianáin)

section 18

These nobles, having set about departing, were seven leagues fromRouen that night, in a small village called La Boissière. As they were leavingRouen, Aodh Óg Ó Néill, the son of Brian, son of Art, separated from the company and lost his way. Maigbhethadh Ó Néill returned toRouen to search for him. Brian's son came in with the company. When Maigbhethadh returned fromRouen he followed the track of another mounted party which had leftRouen. He did not meet his own party till they reached Arras.