Final answer:
Osman I, a 13th-century Turkish warlord, founded what we now know as the Ottoman Empire. His son, Orhan, sustained his father's mission after his demise and expanded their territory. By the 14th century, the empire has surrounded Constantinople, and in 1453, they captured it, making it their capital.
Step-by-step explanation:
The 13th-century Turkish warlord who is considered as the founder of what later becomes known as the Ottoman Empire is Osman I. Osman I, who was a leader under the Turkic principality, raised an army and began to seize territory from the neighboring Byzantines, hence beginning the formation of the Empire. His child, Orhan, continued his work after his death, expanding their territory to include much of northwestern Anatolia. This established an empire that would eventually become a significant player politically, economically, and culturally in Eurasia, and ultimately controlling vast regions, which were diverse in ethnicity, language, and religion.
This empire, named for Osman, was eventually known as the Ottoman Empire. By the 14th century, they had surrounded Constantinople (now Istanbul), the Byzantine city, having expanded their territory into southeastern Europe. In 1453, the city was captured by the Ottoman armies, thereby marking an important victory for the Ottomans and elevating Istanbul as the capital of their increasingly expanding Rule. Over the next century, the Empire extended deeper into Europe, encompassed much of Syria and Palestine, and expanded across North Africa, at its height under Sultan Suleiman I in the 16th Century
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