Thomas was the youngest son of Count Landulf of Aquino, a Lombard noble of the south Italian kingdom. At five he was given as an oblate to the Benedictine monastery of Monte Cassino. At nineteen, against the fierce opposition of his family — they kidnapped him and held him in the family castle for over a year, sending a prostitute to break his vow of chastity (he drove her out with a brand from the fire) — he persisted in entering the new mendicant Order of Preachers.
Sent to study under Albert the Great at Cologne and Paris, the silent and physically heavy young friar (his fellow students called him 'the dumb ox') stunned Albert with the depth of his first lecture. Albert prophesied: 'We call this man a dumb ox, but his bellowing in doctrine will one day resound throughout the world.'
Aquinas spent the rest of his life teaching, preaching, and writing at Paris, Naples, Rome, and Orvieto. He composed the Summa contra Gentiles (1259–65), the Summa Theologiae (begun 1265, unfinished at his death) — a synthesis of Christian doctrine in dialogue with Aristotle and the philosophers of antiquity that no later theologian has equalled — and commentaries on most of Aristotle, on Paul's letters, on Job, on John. He also composed the Office of Corpus Christi at Urban IV's request, including the great hymns Pange lingua, Tantum ergo, Adoro te devote, Lauda Sion, O salutaris hostia.
On December 6, 1273, after celebrating Mass at Naples, he stopped writing forever. Asked why, he answered: 'I cannot, because all that I have written seems like straw to me, compared to what I have seen and what has been revealed to me.' Three months later, journeying to the Council of Lyon, he died at the Cistercian abbey of Fossanova, aged forty-nine.