Constantinople

From Bahaikipedia

Constantinople (Turkish: İstanbul) modern day Istanbul. It was the capital of the Christian Byzantine Empire until the Ottoman's took it over and made it there capital. They renamed it Istanbul. Bahá’u’lláh, along with His family and a group of Bábí's where imprisoned in Constantinople for 4 months. In Constantinople, the Persian authorities along with the Ottoman ones tried to make life as difficult as possible for Bahá’u’lláh and the exiles. Scared of His influence, they later moved them to Adrianople a remote city in the Ottoman Empire. From Adrianople, Bahá’u’lláh would go to the infamous prison city of ‘Akká.

In Constantinople, Bahá’u’lláh composed the Tablet of Ahmad.