The Roman Catholic Diocese of Trebinje-Mrkan is an ecclesiastical territory or diocese

Diocese

A diocese is the district or see under the supervision of a bishop. It is divided into parishes.An archdiocese is more significant than a diocese. An archdiocese is presided over by an archbishop whose see may have or had importance due to size or historical significance...

 of the Roman Catholic Church

Roman Catholic Church

The Catholic Church, also known as the Roman Catholic Church, is the world's largest Christian church, with over a billion members. Led by the Pope, it defines its mission as spreading the gospel of Jesus Christ, administering the sacraments and exercising charity...

 in eastern Herzegovina

Herzegovina

Herzegovina is the southern region of Bosnia and Herzegovina. While there is no official border distinguishing it from the Bosnian region, it is generally accepted that the borders of the region are Croatia to the west, Montenegro to the south, the canton boundaries of the Herzegovina-Neretva...

.

It is the oldest and smallest Roman Catholic diocese of Bosnia and Herzegovina

Bosnia and Herzegovina

Bosnia and Herzegovina , sometimes called Bosnia-Herzegovina or simply Bosnia, is a country in Southern Europe, on the Balkan Peninsula. Bordered by Croatia to the north, west and south, Serbia to the east, and Montenegro to the southeast, Bosnia and Herzegovina is almost landlocked, except for the...

. The diocese was formed sometime before the year 1022. An exact date is not known, but church officials decided to celebrate the diocese's millennium in 1984, estimatiing its foundation at 984

984

Year 984 was a leap year starting on Tuesday of the Julian calendar.- Asia :* Emperor Kazan succeeds Emperor En'yū on the throne of Japan....

. The diocese has its episcopal see in the city of Trebinje

Trebinje

Trebinje is the southernmost municipality and town in Bosnia and Herzegovina. It is administratively part of the Republika Srpska entity and is located in southeastern Herzegovina, some from the Adriatic Sea....

. However, from 1361 to 1391 it was relocated to the island of Mrkan, thus taking on the present double name.

In 1890, the diocese was united with the much larger Diocese of Mostar-Duvno. Since then it has been administered by Mostar-Duvno's bishop (currently Ratko Perić

Ratko Peric

Mons. Ratko Perić is the current Bishop of Mostar-Duvno and Apostolic Administrator of Trebinje-Mrkan.Ratko Perić was born in the village of Tuk in the Rovišće municipality, near Bjelovar in Croatia. After studies in Zagreb and Rome, he was ordained priest on 29 June 1969 in Prisoje...

). However, unlike the rest of the Mostar-Duvno territory, Franciscan

Franciscan

Most Franciscans are members of Roman Catholic religious orders founded by Saint Francis of Assisi. Besides Roman Catholic communities, there are also Old Catholic, Anglican, Lutheran, ecumenical and Non-denominational Franciscan communities....

 priests are not appointed to parishes in Trebinje-Mrkan, as the Franciscan custody does not extend into this region.

On May 1, 1984 the Church of the Birth of Mary in Trebinje was made a cathedral

Cathedral

A cathedral is a Christian church that contains the seat of a bishop...

 by decree. This came to coincide with a symposium held that year under the leadership of Bishop Pavao Žanić

Pavao Žanić

Pavao Žanić was the bishop of Mostar-Duvno in Bosnia and Herzegovina from 1980 to 1993. A leading critic of the alleged apparitions at Međugorje, he was the local ordinary in 1981 when the apparitions began.-Biography:...

 to study the historical and pastoral significance of the diocese. One of the most important parishes in the bishopric is the Shrine of the Queen of Peace in Hrasno

Hrasno

Hrasno is a neighbourhood in Sarajevo, Bosnia and Herzegovina.It is home of the fourth tallest skyscraper in the Balkans, known as the Bosmal City Center....

. Every year thousands gather to celebrate the parish's feast day.