The Martinikerk (Martin's church) is the oldest church in Groningen, Netherlands. The church and its associated tower (the Martinitoren) are named after Saint Martin of Tours (316–397), the patron saint of the Bishopric of Utrecht to which Groningen belonged. The church was a cathedral for a short period during the first bishopric of Groningen (1559–1594). Its organ contains stops dating back to 1450, and was rebuilt and enlarged by Arp Schnitger among others. The church and organ are filmed extensively in the documentary Martinikerk Rondeau.