His original name was Giovanni de' Medici. Pope Leo was born in Florence in 1475 and died in Rome in 1521. He was perhaps the most important of the Renaissance popes, made Rome a center of European culture and raised the papacy to significant political power in Europe.
He was the second son of Lorenzo the Magnificent and Clarice Orsini, and by custom thus destined for ecclesiastical carreer. He received the finest education available in Europe at the court of his father under humanistic tutors such as Pico della Mirandola, Marsilio Ficino, Poliziano, Demetrio Calcondila. From 1489 to 1491 he studied theology and canon law at the University of Pisa, together with Cesare Borgia. In 1492 he became a member of the Sacred College of Cardinals and attempted to take up residence in Rome. The death of his father later in the same year and the election of the new Pope, Alexander VI, however, brought him back to Florence where he lived with his older brother, Piero.
In 1494 he first goes to stay at the court of Guidubaldo da Montefeltro, and then for the next six years he traveled throughout northern Europe. In 1500 he returned to Italy and settled in Rome. Here he dedicates himself to humanistic studies and to contemporary theatre. Named papal legate to Bologna and Romagna in 1511, he supervised the reestablishment of Medici control of Florence the following year.
With the death of Julius II in 1513, the College of Cardinals was summoned to elect a successor. With minimal deliberation the cardinals, who desired a peace-loving successor to the warlike Julius, elected Cardinal de' Medici Pope, who took the name of Leo X.
At 37 years of age the new pope was the personification of Renaissance ideals. Having spent his youth at the court of Lorenzo de' Medici, he had acquired the mannerisms and tastes of one of the most brilliant societies of Europe and posed a sharp contrast to the soldier-pope whom he succeeded. He fit extremely well into the atmosphere of calm and quiet of which Rome was desirous after 10 years under Julius II. Leo was lavish in his spending not only of the church's money but also of his own. Under his patronage Rome again became the cultural center of the Western world. The construction of St. Peter's Basilica - initiated under Julius II - was accelerated, the holdings of the Vatican Library were greatly increased, and the arts flourished. Even the piety of the papacy was revised to some extent after the low reputation it had reached under the Borgia popes (Calixtus III and Alexander VI).
The fifth Lateran Council, called with the hope that it would effect reforms, occupied the new pope during the first five years of his pontificate, but failed to achieve anything. Leo X, who inherited the council before it was a year old, was little inclined to preside over the sweeping reforms that the church so desperately needed on the eve of the Protestant Reformation. The council was dissolved in March 1517, just before Martin Luther's circulation of his famous theses against the sale of indulgences, an activity practiced by Pope Leo to provide income for his building program. Leo condemned the heresies and excommunicated the reformers, but failed to deal effectively with the trouble.
Leo X was not only the head of the Christian Church, he was also the temporal ruler of the Papal States and head of the Medici family that ruled the Florentine Signoria. To exert his influence in Italy he resorted to the common practice of nepotism (granting offices or benefits to relatives, regardless of merit). To the influential archbishopric of Florence he appointed his cousin, and future pope (Clement VII), Giulio de' Medici. He also named his younger brother Giuliano and his nephew Lorenzo to be Roman patricians. Giuliano's premature death in 1516 brought an end to the Pope's plan to create a central Italian kingdom for him.
Perhaps Leo's chief fame rests on his patronage of Raphael, on the continuation of St. Peter's by Bramante, and on his literary circles that included Cardinal Bembo, Cardinal Bibbiena and many others.