Background
He was the youngest son of Gautier II de Termonde, Lord of Termonde (Flemish: Dendermonde) in Flanders.
He was the youngest son of Gautier II de Termonde, Lord of Termonde (Flemish: Dendermonde) in Flanders.
He was probably as Thierry d"Orca and Aymar de Lairon one of the Crusaders who remained in the Holy Land after the end of the Third Crusade. Baldwin there named Thierry as constable. According to Geoffrey of Villehardouin Thierry died in the spring of 1206 at the Battle of Rusion (also Roussillon or Rusium) in Thrace fighting against Bulgarians.