The third hypothesis says that Karaims are the descendants of Israelite tribes from the time of the first Exile by an Assyrian King (720sBCE). The Karaim scholar Abraham Firkovich collected the documents arguing in favor of this theory before the Russian Tsar. He was of the opinion that Israelites from Assyria had gone into the North Caucasus and from there, with the permission of the Assyrian king into the Crimean peninsula. He also claimed that he has found the tombstone of Yitzhak ha-Sangari and his wife who he claimed were Karaims. Whether Firkovich forged some of the tombstone inscriptions and manuscripts is controversial.