Answer:
By the mid-15th century, constant struggles for dominance with its Balkan neighbours and Roman Catholic rivals had diminished Byzantine imperial holdings to Constantinople and the land immediately west of it. Furthermore, with Constantinople having suffered through several devastating sieges, the city’s population had dropped from roughly 400,000 in the 12th century to between 40,000 and 50,000 by the 1450s. Vast open fields constituted much of the land within the walls. Byzantine relations with the rest of Europe had soured over the last several centuries as well: the Schism of 1054 and the 13th-century Latin occupation of Constantinople entrenched a mutual hatred between the Orthodox Byzantines and Roman Catholic Europe. Nevertheless, just as deeply entrenched was the understanding that Byzantine control of Constantinople was a necessary bastion against Muslim control of land and sea in the eastern Mediterranean.
Step-by-step explanation:
The dwindling Byzantine Empire came to an end when the Ottomans breached Constantinople's ancient land wall after besieging the city for 55 days. Mehmed surrounded Constantinople from land and sea while employing cannon to maintain a constant barrage of the city's formidable walls