The name of this Church comes from the battle of Montecatini (1315) during which German soldiers died fighting on the side of the Pisans. In their honour, a German confraternity founded this Church in 1317, and decorated it with the arms of the knights. These decorations were removed some time before 1643.

In 1414 the building was annexed to the Foundlings Hospital (Ospedale dei Trovatelli) and, under the new name of San Giorgio degli Innocenti, became the chapel of the adjacent hospital. Later both Church and Institution were governed by the Ospedale degli Innocenti in Florence (1567) and finally they passed to the Ospedali Riuniti di Santa Chiara (1784), to which they still belong and who, in 1989, conceded their use to the Knights of the Holy Sepulchre (Cavalieri del Santo Sepolcro).

The church is built entirely in brick. A pattern of small bricks enlivens the flat wall of the gabled front, decorated with a row of dead archlets and a double mullioned window. In the lunette above the door is a fresco of the Holy Family painted in the manner of the 14th century by Curzio Rossi in 1932. The south wall of the Church, too, is decorated with dead arches and double mullioned windows. A small belfry stands above the roof.

The simple interior has an early 19th century wooden coffered ceiling and on the walls are 19th century copies of ovals painted (in about 1773) by Giovanni Stella e Giuseppe Soldaini, depicting Christ, the Madonna and Saints On the north wall is a marble altar (1722) above which hangs a canvas with the Massacre of the Innocents by Domenico Ceuli. Above are two 18th century works by Giovan Battista Fanucci and, on the left of the high altar, is an Immaculate Conception, by an unknown 18th century artist.