The Military Order of the Knights of St. Stephen was founded in Pisa by Cosimo I de' Medici, Grand Duke of Tuscany. Pope Pius IV approved the new Order on 1 October 1561 and bade that it follow the Benedictine rule. He conferred the red lanceolate lobed cross on it and named it after Saint Stephen, Pope and martyr, in honour of Cosimo's victory over Siena in 1554, on this Saint's day, 2 August. Cosimo established the Order in the monumental square, later known as the Piazza dei Cavalieri (the Knights' Squa re). Here, Giorgio Vasari constructed two large buildings and a church, dedicated to the Saint, to belong to the Order.
This church, by Papal Bull, became a collegiate church, on 7 July, 1562. Construction was begun by Vasari on 17 April 1565, on the site of the ancient church of St. Sebastian alle Fabbriche Maggiori, where the Ghibellines had held their council on I July 1288, deposing Count Ugolino della Gherardesca from his place as Captain of the People.
The church originally had only one nave, the two lateral ones were to be added in the 17th century and were only consecrated in 1867.
The church itself was consecrated on 21 December 1569 and the first Prior was the Pisan Canon, Mons. Francesco Perignani. Leonardo Bitossi did the sculpting in marble and grey sandstone and Davide Portini was director of works, chief mason was Domenico Celli from Lucca.
The facade, entirely in marble, was modelled on a plan by Don Giovanni de' Medici between 1594 and 1606. The two minor lateral facades were completed according to a design by Pera in 1934.
Interior of the Church
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