Anglo-Saxon ruler has talent to waste (9)
I believe the answer is:
athelstan
'anglo-saxon ruler' is the definition.
'athelstan' can be an answer for 'ruler' (I have seen 'Old ruler' mean 'athelstan' so perhaps 'ruler' could also mean 'athelstan'). I am not certain of the 'anglo-saxon' bit.
'has talent to waste' is the wordplay.
'to waste' indicates an anagram (I've seen 'wasted' mean this).
'has'+'talent'='hastalent'
'hastalent' anagrammed gives 'ATHELSTAN'.
Can you help me to learn more?
(Other definitions for athelstan that I've seen before include "King in the 10th century" , "Historic English king" , "Early English king" , "Old ruler" , "English king, grandson of Alfred the Great" .)