[1] The historian Cyril Toumanoff, frequently cited in modern Western literature, disagreed with this traditional chronology, established by the early 18th-century scholar Prince Vakhushti, and dated Giorgi's rule to the years 1546–1574 and 1574–1582.
Shortly after Giorgi III's accession to Mingrelia, King George II of Imereti arranged a marriage of his heir Bagrat with Dadiani's sister.
The ruler of Guria, Giorgi II Gurieli, seeing in this alliance a danger to his own security, effected a rapprochement with Dadiani's younger brother Mamia, whom he gave his sister in marriage.
[1][3] For a few years, peace reigned in Mingrelia, but, c. 1580, Giorgi Dadiani's uncle Batulia, the lord of Sajavakho, whom the Mingrelian ruler had earlier humiliated by taking his wife, plotted a revolt.
[1][3] Close to the end of his reign, in 1581, Giorgi Dadiani, together with Gurieli, accompanied the king of Imereti, who, at the order of the Ottoman sultan, made a raid in eastern Georgia, in Inner Kartli.