アイルランド・カトリック同盟
Many of the Irish troops in Spanish service returned to Ireland after the Irish Rebellion of 1641 and fought in the armies of Confederate Ireland a movement of Irish Catholics. When the Confederates were defeated and Ireland occupied after the Cromwellian conquest of Ireland, around 34,000 Irish Confederate troops fled the country to seek service in Spain. Some of them later deserted or defected to French service, where the conditions were deemed better.