The kingdoms were Northumbria, Mercia, East Anglia, Essex, Kent, Sussex and Wessex. The latter were the ones who managed to more or less unite England apart from the Danegeld, they were barely holding it together when William arrived. Essex, Kent and Sussex are still counties here, and Northumbria now being called Northumberland. Ireland and Scotland were the same in that they had different kingdoms, sometimes at war sometimes not. Sometimes it would just be playing. In Ireland though the current Troubles started with Henry the Eighth though English kings had fought there it was never about religion until he tried to force Protestantism on them then it began and carries on now.