Blessed John Dominici was born at Florence about A.D. 1350. He was of humble parentage and imperfect education, and had, moreover, an impediment in his speech, so that his first application for admission into the Order of Saint Dominic was refused. He persevered in his request, however, and was received when about eighteen years of age. It was observed, that, in assuming the habit, he seemed to acquire a marvelous nobility of manner; his talents were found to be of the highest order, and he was soon held in great repute for his extraordinary eloquence. Earnestly desiring to devote himself to the ministry of the word, the special office of his Order, he implored the intercession of Saint Catharine of Siena that he might be delivered from the impediment of speech which had hitherto prevented him from preaching. His petition was granted; and from that time he became one of the most renowned preachers of the day; so much so, that, when Saint Vincent Ferrer was invited to preach at Florence, he excused himself on the plea, that, as the city possessed so eloquent an orator as Father John Dominici, there could be no need of him. Blessed John received yet another favour through the intercession of Saint Catharine; for, being at Rome in the Jubilee year and unable by reason of a bad foot to make the visits to the four Basilicas required for gaining the Indulgences, he had recourse to the Seraphic Virgin of Siena, whom he had seen in his youth, and was at once entirely delivered from his infirmity. He was intimately associated with her Confessors and other Fathers who had been her disciples, and he took a leading part in the reform of the Order set on foot by Blessed Raymund of Capua, who appointed him Vicar Provincial of the Roman Province. Later on, we find him endeavouring to restore regular life in the various important Convents of which he was successively superior, and founding a house of strict observance at Fiesole, near Florence, where he gave the habit to Saint Antoninus and to the two artists, Fra Angelico and Fra Benedetto. Blessed John was himself an artist of no mean talent and enriched the choral books of his Convent with beautiful miniatures. He rightly regarded art as a means of instructing the young and the ignorant in the truths of religion and of raising the mind to heavenly aspirations. With this view he greatly encouraged its cultivation both among the Friars and the religious women of the Order.
But Blessed John's title to the gratitude of the faithful in general is chiefly based on the important part which he had in the extinction of the great Schism of the West, which for nearly half a century had divided the allegiance of Christendom. Created Archbishop of Ragusa and Cardinal by Pope Gregory XII., he had a large share in the convocation of the Council of Constance, at which he assisted as that Pontiff's Legate. The great object of the Council was to obtain the resignation of all three claimants of the pontifical dignity, in order that the Fathers might then proceed to the valid election of one, to whose lawful claims none could offer opposition. Blessed John succeeded in inducing John XXIII. to offer his resignation on condition Pope Gregory should also resign. The anti-pope little knew that the holy Cardinal held the formal resignation of that Pontiff in his hand, and was thunderstruck when he immediately produced it. Then, laying aside his Cardinal's hat, Blessed John added these words: "And I, who came as that Pontiffs Legate, also renounce my dignity and my cardinalate;" and so saying he took his place among the Bishops. The Fathers of the Council insisted, however, on restoring him to his rank. The remaining anti-pope, Benedict XIII., better known as Peter de Luna, was deposed; and the Council proceeded to elect Odo Colonna, who took the title of Martin V. The vigor and disinterestedness shown by Blessed John at that crisis restored peace to the Church.
At the request of the Emperor, the holy man was now sent as Apostolic Legate to Hungary and to Bohemia, then much disturbed by the heretical followers of John Huss and Jerome of Prague. In this mission he did much to confirm the people in their adhesion to the true faith and to encourage them in offering a determined resistance to the encroachments of the Turks. Whilst thus engaged, he fell sick at Buda, and, strengthened by the holy Sacraments of the Church, piously fell asleep in the Lord on the 10th June, A.D. 1420, leaving behind him many learned writings. His tomb was desecrated by the Turks when they took and sacked Buda. He was beatified by Gregory XVI.