Cleece was a young Ice Warrior who took part in a pilgrimage led by the Abbot Aklaar. The Seventh Doctor met the abbot, him, his betrothed Esstar and the rest of the pilgrims whilst they were on their way to the Martian north pole.
He believed that he was descended from the warrior caste, unlike the other pilgrims. In fact, his parents were part of the religious caste. Sstaal killed him with the false Sword of Tuburr. (PROSE: GodEngine)