When the Signory, in concert with the Arte de' Mercanti, decided to complete the bronze gates of the Baptistery in the first year of the fifteenth century, they issued a manifesto inviting the sculptors of Italy to prepare designs for competition.

Their call was answered by Giacomo della Quercia of Siena, by Filippo Brunelleschi and Lorenzo di Cino Ghiberti of Florence, and by two other Tuscan artists of less note.
The young Donatello, aged sixteen, is said to have been consulted as to the rival merits of the proofs submitted to the judges.

Thus the four great masters of Tuscan art in its prime met before the Florentine Baptistery.[80] Giacomo della Quercia was excluded from the competition at an early stage; but the umpires wavered long between Ghiberti and Brunelleschi, until the latter, with notable generosity, feeling the superiority of his rival, and conscious perhaps that his own laurels were to be gathered in the field of architecture, withdrew his claim.

In 1403, Ghiberti received the commission for the first of the two remaining gates.
He afterwards obtained the second; and as they were not finished until 1452, the better part of his lifetime was spent upon them.

He received in all a sum of 30,798 golden florins for his labour and the cost of the material employed.
The trial-pieces prepared by Brunelleschi and Ghiberti are now preserved in the Bargello.[81] Their subject is the "Sacrifice of Isaac;" and a comparison of the two leaves no doubt of Ghiberti's superiority.