The city of Constantinople is recaptured by Nicaean forces under the command of Alexios Strategopoulos, re-establishing the Byzantine Empire.

Constantinople, the modern Istanbul, was the capital of the Roman and Byzantine Empire from 330 until its takeover by the Ottoman Empire in 1453. After this, it continued to function as the Ottoman capital until the abolition of the Ottoman sultanate in 1922. It was located at the core of the modern city of Istanbul, on a peninsula at the southeastern tip of Thrace in Europe; with the Bosporus strait and the ancient cities of Chalcedon and Chrysopolis in Bithynia, Anatolia to the east; the Golden Horn and the citadel of Galata (Pera) to the north; the Sea of Marmara to the south; and the Princes' Islands to the southeast.