From AmtWiki

The Stronghand Tournament was originally won by Angus Stronghand Campbell. The winner of the tournament would receive a belt favor marking them as a stronghand, and once accepted byt the rest of the Stronghand, they would be allowed to use the surname Stronghand. Once won they are not allowed to fight in the tournament again.

The winners of the tournament thus far have been:
Squire Kupe Stronghand
Sir Balinor Darkwolf
Raion no Yoto
Squire Raion no Kakeda
Squire Covus Helstaven
Squire Raion no Yukimura

There has been one member of the Stronghand family created not from winning the tournament, but for running it since its inception.
Squire Jolly Callico