Tinmas was a classmate of Karigan G'ladheon at Selium, where he and a group of noble cronies made life difficult for common-born students and those who trended the school on scholarships. He was described as petty and cruel, and his political connections largely shielded him from any reprisal. He was a small youth, short and slight of build, and was once soundly defeated in a bout with practice swords by Karigan G'ladheon. He was publicly scolded for attacking Karigan after the bout ended and her back was turned. His complaints to his Selium-dwelling relations resulted in Karigan's suspension from Selium.
After the execution of his father following a failed coup attempt, Timas Mirwell was invested as The Lord Governor of Mirwell. His steward was Barrett, another bullying classmate. His retained Beryl Spencer as an aide, until the temporary failure of her ability led him to suspect that she was a spy of the King. His staff also included Colonel Birch, the military commander of Second Empire.
He appears to have been an unwilling ally to Second Empire while they congregated in the Teligmar hills in Mirwell Province, and slipped a message to the King's messengers, Karigan G'ladheon and Fergal Duff, that alerted them to the passage of Lady Estora's kidnapping party through the Teligmar Crossroad. He remains under close observation by King Zachary's agents, though Beryl Spencer has been reassigned.