While he was attending the school of the Caracci his preference for the plastic art became evident, and he placed himself under the instruction of the sculptor Conventi. At the age of twenty he was brought under the notice of Ferdinand, Duke of Mantua, who gave him several commissions. He was also much employed about the same period by jewelers and others in modelling in gold, silver and ivory.
After a short residence in Venice he went to Rome in 1625 with an introduction from the duke of Mantua to the pope's nephew, Cardinal Ludovisi, who employed him for a time in the restoration of ancient statues. The death of the duke of Mantua left him to his own resources, and for several years he earned a precarious maintenance from these restorations and the commissions of goldsmiths and jewelers.
In 1640 he executed for Pietro Buoncompagni his first work in marble, a colossal statue of Philip Neri, with kneeling angels. Immediately after, he produced a similar group, representing the execution of Saint Paul, for the church of the Barnabite Fathers in Bologna. These works, displaying great technical skill, though with considerable exaggeration of expression and attitude, at once established Algardi's reputation, and other commissions followed in rapid succession.
The turning point in Algardi's fortune was the accession of Pope Innocent X, of the Bolognese house of Panfili, to the papal throne in 1644. He was employed by Camino Panfili, nephew of the pontiff, to design the Villa Doria Panfili outside the San Pancrazio gate. The most important of Algardi's other works were the monument of Pope Leo XI, a bronze statue of Innocent X for the capitol, and, above all, La Fuega d'Attila, the largest alto-relievo in the world, the two principal figures being about 10 ft. high.
In 1650 Algardi met Diego Velasquez, who obtained some interesting orders for his Italian companion in Spain. Thus there are four chimneys by Algardi in the palace of Aranjuez, where also the figures on the fountain of Neptune were executed by him. The Augustine monastery at Salamanca contains the tomb of the count and countess de Monterey, which was also the work of Algardi.
From an artistic point of view, he was most successful in his portrait-statues and groups of children, where he was obliged to follow nature most closely. In his later years he became very avaricious and amassed a great fortune. He died in Rome on the 10th of June 1654.
See ''Le arti di Bologna disegnate da A. Caracci ed intagliati da S. Giulini, con' assistenza d'Alessandro A. Algardi'' (1740).