Tokat is the capital city of Tokat Province of Turkey in the mid-Black Sea region of Anatolia. It is located at the confluence of the Tokat River (Tokat Suyu) with the Yeşilırmak. In the 2018 census, the city of Tokat had a population of 155,000.

The city was established in the Hittite era. During the time of King Mithradates VI of Pontus, it was one of his many strongholds in Asia Minor.

Known as Evdokia (Evdoksia), ecclesiastically it was later incorporated into the western part of the Byzantine Greek Empire of Trebizond.

After the Battle of Manzikert the town, like most of Asia Minor, came under the control of the Seljuk Turks. After the death of Sultan Suleiman ibn Qutulmish in 1086, the Emir Danishmend Gazi took control of the area, operating from his power base in the town of Sivas. It would be many decades before the Seljuks re-took control of that region, in the reign of Kilij Arslan II.

After the Battle of Köse Dağ, Seljuk hold over the region was lost, and local Emirs such as the Eretna took power until the rise of the Ottomans.

Even under Seljuk Muslim rule, Tokat remained a centre of Pontic Greek culture and the Greek Orthodox church.

Anglican priest and famous Bible translator (Persian and Urdu among other languages) Henry Martyn died 1812 in Tokat while he was on his way from Shiraz back to England and was buried in the Armenian cemetery.

In 1859 was established as a residential diocese of the Armenian Catholic Eparchy of Tokat on territory previously without a proper Ordinary of its Eastern Catholic particular church sui iurus (Armenian Rite in the Armenian language).

The only recorded residential incumbent Eparch (Bishop) of Tokat was Arsenio Avak-Wartan Angiarakian (15 August 1859 – 4 July 1865), emeritate as Titular Archbishop of Tarsus (21 July 1865 – death 8 April 1874).

On 30 May 1892 the diocese was suppressed and its territory reassigned to the Armenian Catholic Eparchy of Sebaste.

In 1972 the diocese was nominally restored as Titular bishopric of Tokat, but is vacant after a single incumbent, of the lowest (episcopal) rank, Titular Bishop Vartan Achkarian, Mechitarists (C.A.M., Benedictine) (28 September 1987 – death 28 July 2012), Auxiliary Eparch of the patriarchal province Cilicia of the Armenians (Lebanon) (28 September 1987 – 1997), Bishop of Curia of the Armenians (1997 – 2002), Auxiliary Eparch of Beirut of the Armenians (Lebanon) (2002 – 11 June 2011).