Excerpts from Books and Wikipedia
"The Safavid dynasty (...) was one of the most significant ruling dynasties of Iran, often considered the beginning of modern Iranian history. The Safavid shahs ruled over one of the Gunpowder Empires. They ruled one of the greatest Iranian empires after the 7th-century Muslim conquest of Iran, and established the Twelver school of Shia Islam as the official religion of the empire, marking one of the most important turning points in Muslim history." [Wikipedia]
"Viewed from the larger historical and geographical perspective, in fact, it would be fair to claim that it was the Muslim states which formed the most rapidly expanding forces in world affairs during the sixteenth century. Not only were the Ottoman Turks pushing westward, but the Safavid dynasty in Persia was also enjoying a resurgence of power, prosperity, and high culture, especially in the reigns of Ismail I (1500–1524) and Abbas I (1587–1629);" [Kennedy: Great Powers, p. 9]