The invasion of the Ostmen was the first of a series of half-conquests which brought all the evils of foreign invasion with none of its benefits.

A stately cathedral of decorated Norman work rose on the site of an earlier church founded by the Ostmen.

A doubtful campaign went on in which the English, attacked now by the Ostmen of the towns, now by the Irish, fought with very varying success, but with prodigies of valour.