Final answer:
The historical figure in question is Shah Ismail, who became the king of the Safavid Empire at age 14 after a series of military victories. He established Shi'ism as the state religion of the empire.
Step-by-step explanation:
The question pertains to a historical figure known as Shah Ismail, who at the age of 14, became the king of the Safavid Empire and is known for conquering the territory of today's Iran. Despite being just 12 years old when he emerged from exile, Shah Ismail's quest for power began in 1499 when he rallied the Qizilbash troops.
The Qizilbash, a military order with distinctive red hats, had fought for his father and brother. In 1501, Ismail entered Tabriz and declared himself the Shah of all Iran, although initially ruling only Azerbaijan and part of the Caucasus. Over time, his forces expanded the empire's borders, making it into what is modern-day Iran by 1511, following a military campaign against the Uzbeks and incursions into eastern Anatolia.
The Safavid Empire under Ismail's leadership introduced Shi'ism as the state religion at a time when most of the Iranian population was Sunni. This decision fostered the enduring divide between Shi'ism and Sunnism that affects Islamic relations to this day. The empire constantly found itself at odds with Sunni neighbors, and this religious division was a source of much conflict during the period.
Shah Abbas I, another significant figure in Safavid history and the grandson of Shah Ismail, is often regarded as the greatest ruler of the Safavid Dynasty. He became Shah at 17 and made substantial reforms, especially in the military and administration, leading to a golden age for Persia. Under Shah Abbas, the Safavid Empire reached its zenith with the capital at Isfahan, a city that to this day is renowned for its stunning Islamic art and architecture.