Educated in Florence at the court of Lorenzo the Magnificent, in
        1493, aged only twenty-four, he became a cardinal. He performed his
        duties but led a worldly life until his ordination to the priesthood
        in 1519. However, he still lived in the style of a Renaissance prince,
        and allowed the advancement of his children and grandchildren to get
        in the way of the best interests of the Church, sometimes with dire
        results.
              In 1534, after the death of Pope Clement VII, he was elected
        pope as he was the oldest, most intellectual of the cardinals who
        promised political neutrality and openly professed the necessity of a
        council. In 1536 he confirmed Pope Clement VII's approval of the
        Capuchin order, a reformed branch of the Franciscans.
               As Pope Paul III he tried to repair the ravages in Rome and
        patronized great artists, especially Michelangelo. He put him in
        charge of construction of the new palace he built in Rome for his
        family, the Palazzo Farnese, commissioned him to fresco another chapel
        in the Vatican, the Capella Paolina, and made him chief architect of
        St. Peter's---a post Michelangelo held until his death in 1564, long
        enough for his great design for the dome to be on the way to
        accomplishment. Paul III also saw to Michelangelo's undertaking in the
        Sistine chapel, 'The Last Judgement', completed in 1541.
              In 1540, despite opposition from some of the cardinals, he
        officially approved of the Society of Jesus and thereafter continued
        to help Ignatius Loyola and his order with support and benefits. He
        appointed a number of worthy men to the college of cardinals,
        including Reginald Pole, and so began to change its character for the
        better. He tried, but failed, to bring about peace between Francois I,
        King of France, and the Emperor Charles V, intending to unite them in
        a crusade against the Turks.
              His principal claim to greatness is his successful convocation
        of the Council of Trent which, after many frustrated attempts, finally
        opened in December 1545. Though almost as distrustful of the emperor
        as Pope Clement VII had been, Paul was able to co-operate with him. He
        had hoped that the council would end a few months after an almost
        routine condemnation of Lutheran teaching and without touching reform
        of the Church, but the council continued for eighteen years until
        1563.
 

Source:  "The Papacy", by Paul Johnson.