Rory left two sons, Callagh and Ruairí Óge. Callagh, who was brought up in England, was called by the English 'The Calough,' and, as he describes himself as of Gray's Inn in 1568, he may be the John Callow who entered there in 1567 (Foster, Reg. of Gray's Inn, p. 39). In 1571 Ormonde petitioned for the Calough's return, and soon afterwards he came back to Ireland, and was granted an estate at Balyna, near Moyvalley, County Kildare in 1574. In 1582 he was thought a sufficiently strong adherent to the English to receive a grant of land in Leix. . Callagh was the father of Rory O'Moore, "alias" Sir Roger Moore, who was a leader of the Irish Rebellion of 1641.