His rule was marred by the long-standing struggle between the Imeretian crown seeking to subdue Mingrelia and Mingrelian efforts to win full independence, a continuation of the conflict which had plagued western Georgia for centuries.
He soon managed to escape with the help of his uncle, Giorgi Dadiani, and Kaikhosro Gelovani, governor-general of Lechkhumi, and entrenched himself in the fortress of Nogi in Mingrelia, which Solomon failed to take and fell back to Kutaisi.
As a result, the king had to recognize Grigol as prince of Mingrelia, who, in his turn, conceded the fiefdom of Salipartiano to his estranged brother Manuchar, Solomon's protégé.
Grigol quickly regained his position, but he had to concede the fort of Anaklia and to surrender his own son and heir, Levan, as an honorary hostage to Kelesh Bey, ruler of Abkhazia, in exchange of received support.
The Russian diplomats, having secured Ottoman neutrality on the Mingrelian issue, formalized the agreement with Dadiani with the Treaty of Dadichala on 1 December 1803, which was ratified by Tsar Alexander I on 20 March 1804.
Grigol then tried to exploit Russia's increasingly tense relations with Imereti and went so far as to petition the Tsar to depose Solomon II as king and to replace him with his cousin, Prince Ioann of Georgia.
[9] Tsitsianov himself exploited the suspicion of homicide to remove Grigol's treating doctor, the Italian Capuchin missionary Nicola di Rutigliano, who was suspected of anti-Russian intrigues.