Following the Fourth Crusade (1204), the city was captured by the Frankish crusaders. Initially, it was given as a fief to the Knights Templar, who rebuilt its fortress. In 1209–10 the Templars were evicted due to their support to the rebellion of the Lombard barons of the Kingdom of Thessalonica. The Latin Emperor Henry of Flanders confiscated the city (and neighbouring Ravennika) and made it an imperial domain under a "bailli", possibly Rainerio of Travale. Under Frankish rule, it was the seat of a Roman Catholic bishop ("Dioecesis Sidoniensis" or "Cythoniensis"), probably a suffragan of the Latin Archbishop of Neopatras. In , or shortly after 1223, the two towns were captured by the Epirote Greeks. Lamia remained in Greek hands until it was surrendered again to the Franks of the Duchy of Athens in 1275 as part of the dowry of Helena Angelina Komnene, daughter of John I Doukas, ruler of Thessaly. It thereby again became a Catholic see.