Shapur II (Middle Persian: 𐭱𐭧𐭯𐭥𐭧𐭥𐭩 Šābuhr, 309–379), also known as Shapur the Great, was the tenth King of Kings (Shahanshah) of the Sasanian Empire. He took the title at birth and held it until his death at age 70, making him the longest-reigning monarch in Iranian history. He was the son of Hormizd II (r. 302–309).
His reign saw the military resurgence of the country and the expansion of its territory, which marked the start of the first Sasanian golden era. Thus, along with Shapur I, Kavad I and Khosrow I, he is regarded as one of the most illustrious Sasanian kings. His three direct successors, on the other hand, were less successful. At the age of 16, he launched enormously successful military campaigns against Arab insurrections and tribes.