Tiepolo served his apprenticeship with Gregorio Lazzarini and the influence of Tenebrism, as exemplified by Piazzetta, can be seen in early works such as The Sacrifice of Isaac (Venice, church of Santa Maria dei Derelitti, 1716) and the Madonna of Mount Carmel (Milan, Brera, 1720–22). At the same time, however, these paintings already display a mature artistic personality in their compositional freedom and focus on movement as well as the lightness with which the figures are defined. He joined the Venetian guild of painters in 1717 and married Maria Cecilia Guardi, the sister of Francesco and Giovanni Antonio, two years later. They had ten children, some of whom were to follow in their father’s footsteps (Giandomenico and Lorenzo in particular). The series of Episodes from the Life of Septimia Zenobia, Queen of Palmyra painted for Ca’ Zenobio in Venice probably dates from this period and provides evidence of the interest taken by patrician families in the young artist. Tiepolo’s first great fresco was painted in Palazzo Sandi in 1724, followed a few years later by the wall paintings for the Archbishop’s Palace in Udine, where a “Neo-Veronese” approach is evident in the lighter palette and even greater weightlessness of the figures. The artist’s renown thus spread beyond the borders of the Venetian Republic to Milan (Palazzo Archinto and Palazzo Dugnani, 1731) and then to Bergamo in Venetian territory (the Colleoni Chapel, 1732). Having returned to Venice, Tiepolo produced frescoes for the city’s churches as well as great altarpieces (Venice, church of the Gesuati). He also treated non-religious subjects in canvases such as Apollo and Daphne (Louvre) and Jupiter and Danae (Stockholm). He returned to Milan in 1740 and produced frescoes for Palazzo Clerici followed by a series on Antony and Cleopatra (1746–47) for Palazzo Labia in Venice. It was at the end of 1750 that he and his sons Giandomenico and Lorenzo were commissioned to produce the cycle of events in the life of Emperor Frederick Barbarossa, which constitutes the peak of 18th-century decorative painting, in the palace of the Prince Bishop of Würzburg, where he stayed for three years. The great cycle of frescoes for Villa Valmarana, Vicenza, featuring episodes drawn from the classical and Renaissance epics, was produced in 1757.
The height of Tiepolo’s fame came with the summons to the court of Charles III of Spain. Having arrived in Madrid with his sons in 1762, he produced decorations for various rooms in the royal palace as well as numerous works for other royal residences and churches. The change in cultural climate characterised by the introduction of Neoclassicism, whose foremost representative in Madrid was Anton Mengs, had a negative impact on the last years of the artist’s career, and he died in the Spanish capital in 1770.