Ruled, showing no doubt (7)
I believe the answer is:
decided
I believe this is a double definition.
'ruled' is the first definition.
(I've seen this in another clue)
'showing no doubt' is the second definition.
(having made a decision)
(Other definitions for decided that I've seen before include "Made up one's mind" , "Resolute; settled" , "Made mind up, being unequivocal" , "Came to a resolution" , "Determined - settled" .)