In 1621 Pope Paul V Borghese was succeeded on the throne of St. Peter by another admiring friend of Bernini's, Cardinal Alessandro Ludovisi, who became Pope Gregory XV: although his reign was very short (he died in 1623), Pope Gregory commissioned portraits of himself (both in marble and bronze) by Bernini. The pontiff also bestowed upon Bernini the honorific rank of 'Cavaliere,' the title with which for the rest of his life the artist was habitually referred. In 1623 came the ascent to the papal throne of his aforementioned friend and former tutor, Cardinal Maffeo Barberini, as Pope Urban VIII, and henceforth (until Urban's death in 1644) Bernini enjoyed near monopolistic patronage from the Barberini pope and family. The new Pope Urban is reported to have remarked, "It is a great fortune for you, O Cavaliere, to see Cardinal Maffeo Barberini made pope, but our fortune is even greater to have Cavalier Bernini alive in our pontificate." Although he did not fare as well during the reign (1644-55) of Innocent X, under Innocent's successor, Alexander VII (reigned 1655-67), Bernini once again gained pre-eminent artistic domination and continued in the successive pontificate to be held in high regard by Clement IX during his short reign (1667-69).