Vameq was the younger son of Mamia II Dadiani, brother of Liparit I, and a paternal uncle of Shamadavle, on whose death he succeeded as duke of Mingrelia in 1474.
[1] The circumstances of Vameq's accession are not specifically mentioned in the Georgian sources, but the Venetian patrician Ambrogio Contarini, arriving in Mingrelia in July 1475, found the country in troubles occasioned by the death of its ruler.
As Bagrat grew stronger by expanding his sway into eastern Georgia, over Kartli, Vameq was anxious to protect his autonomy from the crown.
Defeated by the returning king, Vameq sued for peace and begged Bagrat to leave him as duke in exchange of an oath of loyalty.
[3][4][5] Bagrat's death in 1478 provided Vameq with the opportunity to avenge his humiliation by undermining an attempt by the late king's son, Alexander, to seize the crown and aiding the rival monarch, Constantine II of Kartli, in taking hold of Imereti in 1479.