The Diocese of Trebinje (Trebinje-Mrkanje) is one of the oldest in Bosnia and Herzegovina, and was first mentioned in the Bull of Pope Benedict VIII in 1022. The construction of the Cathedral of the Blessed Virgin Mary began in 1880, immediately after the arrival of the Austro-Hungarian army, and was completed in 1884. In 1984, the former parish church was declared a Cathedral Church, on the occasion of the 1000th anniversary of the Trebinje Diocese and 100th anniversary of the church. In 2006, the Cathedral of the Blessed Virgin Mary was declared a national monument of Bosnia and Herzegovina.