Its existence is mentioned as early as 1061. Founded by the family Buzzaccherini-Sismondi and originally dedicated to Saint Martin, it had once an hospital annexed to it.The Romanesque façade shows typical features of the Pisane medieval architecture, such as the blind arcades, the lozenges and the use of bichrome stones (present also in the city's cathedral). In the upper part is a large mullioned window.The interior, despite a fire in 1675, has maintained the original basilica plan with a nave and two aisles. The marble columns have capitals decorated with Romanesque-style sculpted figures. It houses a rare cross painted on a gilded panel with the Crucifix and Histories of the Passion.