Took part in the campaign against Edward Bruce in 1315-18, and took part in the final battle at the hill of Faughart near Dundalk, in which Bruce was killed on 14 Oct 1318. John was already a knight by then. In 1343 he levied a fine together with his wife, Catherine de Foleville and made a settlement on male heirs so that the lands of Gerardstown and Follistown should not pass out of the Cusack family through an heiress. The last record of him is 4 Feb 1346 when he was a witness of a grant to John Stanley, burgess of Drogheda. He had 11 sons.9