The Ecumenical Patriarchate of Constantinople (also known as the Patriarchate of Constantinople or the Greek Orthodox Patriarchate of Constantinople) is an autonomous Eastern Orthodox Church with jurisdiction over several countries, including Turkey. 

It is the spiritual centre of the Eastern Orthodox Church and is headquartered in Istanbul, Turkey.

The Ecumenical Patriarchate of Constantinople traces its origins back to the 4th century AD when the city of Constantinople (now Istanbul) was founded by the Roman Emperor Constantine the Great. 

The Patriarchate was established as the spiritual and administrative centre of the Eastern Orthodox Church, and it has played a significant role in the history and culture of the city ever since.

The Ecumenical Patriarchate of Constantinople is an important site for the Eastern Orthodox community in Istanbul, and it is a popular destination for tourists and pilgrims. 

It is home to several historic churches, monasteries, and other religious sites and is a centre of religious and cultural activity in the city. Whether you're interested in religion, history, or culture, the Ecumenical Patriarchate of Constantinople is a must-see destination in Istanbul.