What empire did the Ottomans conquer to occupy Constantinople?

the Byzantine Empire's

'Conquest of Istanbul') was the capture of the Byzantine Empire's capital by the Ottoman Empire. The city fell on 29 May 1453, the culmination of a 53-day siege which had begun on 6 April 1453.

answer: economic globalization is the increasing economic integration and interdependence of national, regional and local economies across the world through an intensification of cross-border movement of goods, services, technologies and capital