Located in Via di Porta Latina, the small octagonal oratory was built at the beginning of the 16th century, perhaps on an older circular shrine. The project is ascribed to Bramante, Antonio da Sangallo the Younger or Baldassarre Peruzzi; it was certainly built at the expense of the French prelate Benoît Adam, remembered on one of the two gates with the motto “Au plaisir de Dieu”.
In 1658 Cardinal Francesco Paolucci, a noble from Forlì and a pupil of Cesare Baronio, paid the restoration of the small oratory. The works were entrusted to Francesco Borromini who modified the covering, creating a drum with a high stucco frieze and a conical covering ending in a bundle of leaves on which stands a globe decorated with roses (alluding to the heraldic coat of arms of the Paolucci family). In 1967 the original finial was removed and replaced by a plaster copy. The original is now on a plinth in the loggia of San Giovanni a Porta Latina, the Rosminian basilica nearby which has responsibility for the chapel.
Simultaneously with Borromini’s restoration, the walls of the small oratory were adorned with stuccos and frescoes attributable to Lazzaro Baldi, a pupil of Pietro da Cortona, depicting Saint John’s attempted execution. Tradition relates that in this place the apostle was immersed in a vat of boiling oil from which he emerged unharmed.