In the Roman era, triumphal arches were monuments used to commemorate the great deeds of emperors and military leaders. They usually consisted of a single arch supported by a heavy pier at either side, the whole structure then capped by a quadrangular attic onto which a commemorative inscription was added to explain the reasons for its construction. After a successful military campaign, the person honored would enter Rome triumphantly by passing through the arch in grand procession. In the Early Christian era, the triumphal arch motif was used to separate the apse of a church from the nave as symbolic reference to the triumph of Christianity over paganism. In the Proto-Renaissance, the triumphal arch became a surface where religious scenes that instructed the faithful could be rendered, as Giotto's fresco of the Annunciation on the triumphal arch of the Arena Chapel in Padua (1305) denotes. In the Early Renaissance, architects began utilizing the triumphal arch motif for the façades of religious buildings. Filippo Brunelleschi was the first to do so in the Pazzi Chapel in Santa Croce, Florence (1433-1461). Leon Battista Alberti followed suit with the Tempio Malatestiano in Rimini (beg. 1450) and at Sant'Andrea, Mantua (beg. 1470).
Historical dictionary of Renaissance art. Lilian H. Zirpolo. 2008.