In 1744, Erekle II and his father Teimuraz II were granted the kingships of Kakheti and Kartli respectively by their overlord Nader Shah, as a reward for their loyalty. Following Nader Shah's death in 1747, Erekle II and Teimuraz II capitalized on the eruption of instability, and declared "de facto" independence. After Teimuraz II died in 1762, Erekle II succeeded his father as ruler of Kartli, and united the two kingdoms in a personal union as the Kingdom of Kartli-Kakheti, becoming the first Georgian ruler to preside over a politically unified eastern Georgia in three centuries. At about the same time, Karim Khan Zand had ascended the Iranian throne; Erekle II quickly tendered his "de jure" submission to the new Iranian ruler, however, "de facto", he remained autonomous throughout the entire Zand period.