When was St. Dominic de Guzman canonized?

Saint Thomas was declared a saint because of his martyrdom. The canonization process did not come into existence until the 12th century. In the primitive Church, martyrs were immediately recognized as witnessing to the perfection of Christian life on earth, having shown the ultimate proof of their love for Christ by the offering of their lives. By the sacrifice of their lives for Christ, they attained Heaven in eternal glory and were indissolubly united to the Lord, the Head of the Mystical Body.
The Apostles, like many early saints, were not formally canonized, but were recognized as saints by the practice of the faithful. The traditional day of the Feast of St. Thomas is December 21st - the traditional day of death. Recently, it has been transferred to July 3rd - the day of the translation of his relics.