Narrated by Ibn ‘Asaakir, from Maseerah b. Jaleese, where he heard the Prophet ﷺ:  

“This matter (the Khilafah) will continue after me in Al-Madina, then (move to) Al-Shaam, then to the peninsula, then to Iraq, then to the city, then to Bait-ul-Maqdis. So if it reaches Bait-ul-Maqdis, then it would have reached its (natural resting place); and no people who remove it (i.e. the capital of the Khilafah) from their land will ever get it back again (for them to be the capital again).”

The scholars said they believe that what he ﷺ meant by ‘the city’ is the city of Heraclius (Constantinople).