A stela with the inscription of the Urartian king Menua (810 to 785 B.C.) reports about the construction of an irrigation channel in the country of Erinu. The island was fortified in the fourth century by the Armenian Rschtuni family. The foundation of a monastery on the island is documented for the year 653 by Theodoros Rštuni. In the second half of the ninth century the island came under the rule of the Artsruni.

Akdamar, also Ahtamar, is the second largest island in Lake Van. From 908 to 1021 the island was a palace of the Armenian kings, 920/931 - 950/992 the residence of the Catholicos of Dvin and the seat of the Catholicos of Aghtamar from 1116 to 1895.

The island is especially famous for its Armenian church, the "Church of the Holy Cross". The church forms the remains of a town with monastery and palace complex built between 915 and 921 by the architect and former sculptor Manuel on behalf of Gagik Arzruni, King of Vaspurakan.

The exterior walls of the church are richly decorated with reliefs depicting many well-known biblical stories, such as those of Adam and Eve, Jonah and the Whale or David versus Goliath. In addition, 30 animal species have been discovered on the reliefs, some of which are now extinct or on the verge of extinction. The reliefs show the fauna of Anatolia at that time. Such rich sculptural decoration was otherwise unknown at that time. In the West, the development of the building sculpture did not begin until about 100 years later. Inside the Kreuzkirche, the walls are painted with frescoes, some of which are still preserved.

Until 1895 the church served as the Patriarchal Cathedral for the regionally important Catholicate of Aghtamar of the Armenian Apostolic Church. After the death of the last Catholic of Aghtamar, Kachatur III. (1864-1895), the seat remained vacant. In 1910, the diocese of Aghtamar comprised 130 parishes, 203 churches and 70,000 faithful. In 1915 the monastery was destroyed, the church looted and the monks killed.

Wall relief

By decision of the Ottoman Ministry of Justice and Culture of 10 August 1916, the Catholicate of Aghtamar was abolished. In 2005, the Turkish government decided to restore the historic building. On March 29, 2007, the Turkish government opened the medieval Armenian church without a Christian cross as a cultural monument. On September 19, 2010, for the first time in about 95 years, a Christian service was held in the church. Previous differences such as putting up a cross were resolved. Besides Turkish Armenians, many Armenians from Armenia and the USA came to the two-hour fair. At the beginning of October, a 2-meter cross weighing 110 kg was placed on the church.

Wall relief