An Armenian deputy of the Justice and Development Party (AK Party) has condemned a tweet by an Armenian diaspora body that called to revert Istanbul's name back to Constantinople, the capital of the Byzantine Empire until Ottoman Turks conquered the city in 1453.

Markar Esayan on his Twitter account said, "Istanbul will last forever."

Esayan went on to say that it was the Turks that gave freedom of religion to Armenians in the 15th century, after years of pressure from the Byzantine Empire, also known as the Eastern Roman Empire.

"Instead of Byzantine pressure, Fatih Sultan Mehmet, after conquering Istanbul, established The Armenian Patriarchate in 1461," said Esayan and added, "Shame on you."

Esayan, a former journalist who graduated from Armenian elementary and high schools in Turkey, became a member of the Turkish parliament representing his hometown Istanbul in 2015.

The Armenian National Committee of America, founded in the U.S. in 1941, has been waging a smear campaign against Turkey and Turks across the U.S. and the world.

The Byzantines had ruled their realm from Constantinople for more than 1,000 years.After transforming the city into the capital of the nascent Ottoman Empire, Fatih Sultan Mehmet established the Greek and Armenian Patriarchates and bestowed all other residents of the conquered city with civil rights and legal protection regardless of race and religion.

According to historians, it was an unprecedented gesture in medieval European Christendom.

In the words of British historian George Eversley: "This great act of tolerance of Mahomet [Fatih Sultan Mehmet] was far ahead of the political ethics of the Christian powers of Europe at that time."