The seat at the head of the table is always saved for the patriarch of the family.
After his father died, Thomas stepped up to the role of family patriarch.
It is his duty to act as regent; it is his duty to compose the dissensions in the principality of Antioch, and to repress the violences of the prince towards his patriarch (1154); it is his duty to reconcile Antioch with Edessa, when the two fall to fighting.
The assizes may speak of patriarch and king as conjoint seigneurs in Jerusalem; but as a matter of fact the king could secure the nomination of his own patriarch, and after Dagobert the patriarchs are, with the temporary exception of Stephen in 1128, the confidants and supporters of the kings.
The Coptic patriarch uses an iron cross-staff.