St. Minias was by tradition the first evangeliser and Christian martyr in Florence. Minias is thought to have been a Greek merchant or possibly an Armenian prince who left his home to make a pilgrimage to Rome. In about 250, he arrived in Florence and took up life as a hermit. He became a victim of the persecutions of the Emperor Decius (249-251 A.D.) and was beheaded. Legend has it that, after his decapitation, he picked up his head, put it back on his shoulders and went to die in the cave on Monte alle Croci where he had lived as a hermit. That cave is now the location of the oratory and the church that bear his name.

It was constructed sometime after the year 1000 on top of a pre-existent Oratory that had been built by St. Miniato, the first evangelizer and Christian martyr in Florence. Victim of the persecutions of the Emperor Decius (249-251 A.D.), Miniato is thought to have been an Armenian prince: the legend narrates that, after his decapitation, he picked up his head, put it back on his neck and went to die in a cave on Monte alle Croci, where he had lived as a hermit and where later the oratory and the church that bear his name were to be built.

Construction on the temple, one of the finest examples of pure Florentine Romanesque architecture, first started in 1018, thanks to Bishop Ildebrando, and continued until 1207.

The facade was carried out in white Carrara and green Prato marble (12th-13th centuries) and divided into two orders linked together by rhombiform inlaid work, in allusion to the "opus reticolatum", the typical system used during the Roman Empire for building walls; it was also used by Leon Battista Alberti for the base of Palazzo Rucellai.

The interior (where additions were carried out up until Baroque times) is divided into three naves, with a beautiful inlaid marble floor decorated with the Symbols of the Zodiac (11th century) in the centre.

The raised Presbitery is formed by a rare Tuscan-Romanesque sculptoral complex of classical inspiration: the altar, enclosed by a marble transenna (1207), the square pulpit (the work of Giovanni di Gaiole and Francesco di Domenico) and the lectern, supported by the eagle of St. John the Evangelist. The Choir contains a mosaic of the enthroned Christ in benediction (1297, restored by Alessio Baldovinetti in 1491).