Alba
The ruler of Alba was King Indulf (The Aggressor), who had ruled since 954 and would continue to do so until 962.
Deheubarth
The ruler of Deheubarth was King Owain ap Hywel ap Cadell, who had ruled since 950 and would continue to do so until 986.
England
The ruler of England at the beginning of 959 was King Eadwig (Edwig All-Fair), who had ruled since 955. This year, King Eadgar I (Edgar the Peaceable) would take over.
Gwynedd
King Iago ab Idwal together with his brother King Idwal ab Idwal (Idwal the Junior) until Iago imprisoned him to rule alone.
Strathclyde
The ruler of Strathclyde at this time was likely to have been King Dyfnwal map Owain.