Shortly after he acceded to the princely throne, Simon repaired to the Ottoman provincial capital of Akhaltsikhe for negotiations with the local pasha Isaq to ease Turkish pressure on Guria.
On his way back, Simon's entourage was ambushed by the Muslim Georgian clansmen of Adjara, and the prince was taken captive by the Adjarian chieftain Selim Bey, who released Simon after the latter agreed to marry off his 5-year-old daughter Kesaria to Selim's son Abdi Bey.
[2] In a civil war in the neighboring Kingdom of Imereti, whose monarchs claimed suzerainty over Guria, Simon supported David II, but he then made common cause with the eventual winner Solomon II.
In 1790, the king of Imereti as well as princes-regnant of Guria and Mingrelia signed a treaty of alliance with Erekle II, ruler of the eastern Georgian kingdom of Kartli-Kakheti, in which Erekle was recognized as chief and doyen of the Georgian potentates.
[2] Simon was married to Princess Marine (died 4 March 1814), daughter of the influential Imeretian nobleman, Prince Kaikhosro Tsereteli.