Quba rose to prominence in the 18th century. In 1747, Nadir Shah ruler of the Persian Empire was assassinated. That same year, Hussein-Ali, the Shah's designated ruler of the region, decided to attempt to unify the Azeri khanates as an independent kingdom. One of his first moves was moving his capital from the less defensible Xudat in the Caspian lowlands to Quba where he built a fortress. Hussein-Ali died in 1757 and his son Fatali Khan carried on the expansion with Quba reaping the riches of its status as the capital. Some ruins from this period, such as Çirax Qala on the way to Baku, exist today.