Masaccio was born in Castel San Giovanni (now called San Giovanni Valdarno, province of Arezzo) on 21 December 1401. Already by October of 1418 he was working as a painter and living in Florence. It is not clear how his training took place; he could have first learned the rudiments of the trade from another painter from his hometown, Mariotto di Cristofano, who was related to his family by marriage and by 1419 also living in Florence. An apprenticeship in the workshop of Bicci di Lorenzo is also possible, as Masaccio's younger brother, Giovanni, was learning to paint with Bicci in 1421. More important in his formation than these relatively minor painters, however, could have been masters like Giovanni di Francesco Toscani, Gentile da Fabriano (after 1420), and the great sculptor Donatello, who was so keenly interested in problems of painting and perspective. On 7 January 1422 Masaccio, already with his own workshop, enrolled in the Arte dei Medici e Speziali (guild of doctors and pharmacists, to which painters also belonged), and on 23 April of the same year he finished his first dated work, the triptych in the church of San Giovenale in Cascia (now in the Pieve di San Pietro in Reggello). Some time afterward he obtained the commission for a fresco in the cloister of the Carmine to commemorate the consecration (on 19 April 1422) of the Carmelite church in Florence. This work, which came to be known as the "Sagra," was destroyed in the sixteenth century, but Masaccio was praised for it in early sources (such as Vasari) for his originality in rendering figures as fully three-dimensional solids and for the realism of his portraits. In 1424 the artist enrolled in the Compagnia di San Luca, the confraternity of painters, and probably in that same year began his collaboration with Masolino, whom Vasari incorrectly believed to be his master. Masolino, about to depart for a long stay in Hungary, had to request Masaccio's assistance in completing some of his commitments. Masaccio's hand can be detected in the Madonna and Child with Saint Anne and Angels for the church of Sant'Ambrogio (now in the Uffizi), in which the younger master executed the figures of the Madonna, the Child, and the angel at the upper right; he also painted about half of the mural decoration of the Brancacci chapel (comprising stories from the life of Saint Peter) in the church of the Carmine. Masolino probably frescoed the now-destroyed vault of the chapel alone, perhaps as early as 1424. He is documented at the church the following year, with Masaccio at his side, until September, when he left for Hungary. In the chapel Masaccio painted the Expulsion from Paradise, Tribute Money, and Saint Peter Baptizing in the upper register and Saint Peter Healing the Sick, Saint Peter Distributing Alms and the Raising of the Son of Theophilus in the lower. While painting this last scene (which he left unfinished, to be completed some sixty years later by Filippino Lippi) Masaccio interrupted his work in the chapel and moved to Pisa, where numerous payments made to him (from February to December 1426) document his progress in the creation of a polyptych for Pisa's church of the Carmine. The polyptych has since been dismembered and in part lost; the surviving panels are now preserved in the Gemäldegalerie in Berlin, the National Gallery in London, the J. Paul Getty Museum in Los Angeles, the Museo di Capodimonte in Naples, and the Museo Nazionale in Pisa. On 23 January 1427 Masaccio was still recorded in Pisa, but on July 29 he presented his tax return in Florence. Probably in the same year he frescoed the Trinity with the Virgin, Saint John and a pair of donors in the church of Santa Maria Novella, and probably later that year left for Rome, where he began an altarpiece for the Colonna chapel in the basilica of Santa Maria Maggiore. He only finished one lateral panel (Saints John the Baptist and Jerome, now in the National Gallery in London) and began another (Saints Peter and Paul, now in the John G. Johnson Collection, in the Philadelphia Museum of Art) before his death. After Masaccio's death this unfinished painting and the remaining panels of the altarpiece were entrusted to Masolino for completion. In the tax rolls of Florence for 1429, next to Masaccio's name, which has been crossed out, there is the notation "dicesi è morto a Roma" ("said to have died in Rome"). Since the oldest sources report that he died at twenty-six or twenty-seven years of age, the year of his death is probably 1428. Already his own contemporaries realized the extraordinary importance of Masaccio's contribution to the development of Italian painting. He raised the humanity populating his paintings to a new dignity through the physical concreteness of the forms and rigorous perspective of the space that surrounds them, offering a standard to be imitated for generations of Florentine artists. Indeed, according to Vasari's testimony, until Michelangelo's time the city's best painters went to the Brancacci chapel to study and imitate Masaccio's frescoes. [This is the artist's biography published, or to be published, in the NGA Systematic Catalogue]  Vasari, ed. Milanesi, 2 (1878): 298-299.
Longhi, Roberto. "Fatti di Masolino e di Masaccio." CdA 5 (1940): 145-191. Reprinted in
Edizione delle opere complete di Roberto Longhi. 14 vols. Florence and Milan, 1956-2000. Vol. 8, 2 parts. Part 1 (1975).
Fatti di Masolino e di Masaccio....