Thomas Cajetan was born in Gaeta, Kingdom of Naples on 20 February 1469. He entered the Dominican Order at the age of fifteen, and he became known as a promising theologian. In 1511, he supported the Pope against the Council of Pisa, and he became a Cardinal and Archbishop of Palermo in 1517. In 1519, he drew up the excommunication bill against Martin Luther, and he helped to secure the election of Pope Adrian VI. He retained his influence under Pope Clement VII, and he died in 1534.