He was born in a small town in Lombardy, in a family of builders, however it was Rome that became the center of his architectural and sculpting activities. He was taught his profession by Jacopo Barozzi da Vignola, however, he achieved fame by completing the designs of the great Michelangelo (Michelangelo Buonarroti), seeing himself as his student and successor. The one that was the most prestigious for him, was the planned by the master new arrangements of the Capitoline Square (Piazza del Campidoglio) along with adjacent buildings and the monumental steps leading to them. Another challenge and a rung in the ladder of his career was becoming the supervisor of the work on St. Peter’s Basilica (San Pietro in Vaticano). Upon his shoulders fell the responsibility of finishing the church dome. Not only did he succeed in putting into effect the idea of the divine Michelangelo, he also undertook the risky task of raising the dome by almost four meters. We can only imagine what would have happened if he had miscalculated, while the altered proportions of the dome would not meet the esthetic and technical expectations.

After the death of his master, Vignola, della Porta took over the supervision of the construction of the Jesuit Church of Il Gesù, for which he designed the façade, the one which would in time become the most recognizable “brand” of Jesuit architecture and whose forms, promoted in drawings would reach the farthest parts of the world, wherever Jesuits set their feet and where in the image of the one found in Rome, they would built their churches.

The most important architectural commissions of Giacomo della Porta in Rome:

• Urban arrangements of Piazza del Campidoglio according to the design of Michelangelo, 1563

• Façade of the Palace of Conservators (Palazzo dei Conservatori) at Capitoline Square according to the design of Michelangelo, 1605

• Completion of the dome of the Basilica of San Pietro in Vaticano according to the design of Michelangelo, 1588-1590

• Completion of the construction, dome and façade of the Church of Il Gesù, 1584

• Façade of the Church of San Luigi dei Francesi

• Façade of the Church of Santa Maria ai Monti

• Church of Santa Maria Scala Coeli in the complex of San Paolo alle Tre Fontane

• Façade of the Church of San Nicola in Carcere

• Santissimo Crocifisso Oratory, 1568

• Façade of the Church of Santissima Trinità dei Monti

  Some of the fountains and sculptures designed by Giacomo della Porta:

• Fountain on Piazza del Popolo

• Original form of the Fontana di Nettuno and Fontana del Moro on Piazza Navona

• Two fountains on Piazza Farnese

• Fountain in front of Palazzo Borghese

• Fountain on Piazza della Rotonda in front of the Pantheon

• Original form and setting of Fontana delle Tartarughe on Piazza Mattei
• Fontana dei Catecumeni on Piazza della Madonna dei Monti
• Fontanna on Piazza Campitelli
• Fontana del Mascherone di Santa Sabina

• Fontana della Terrina in front of the Church of Santa Maria in Vallicella

• Fountains on Piazza Colonna

• Fountain in front of the Church of Santa Maria in Trastevere

• Fountain at via Giulia
• Marble group Christ Delivering the Keys to Heaven to St. Peter, Church of Santa Pudenziana