Svimon became involved in the politics and administration of the country during the regency of his half-brother, Vakhtang, who ruled Kartli, with his capital at Tbilisi, in the absence of the two successive kings, his uncle George XI and his brother Kaikhosro, at the Safavid Iranian military service in Afghanistan, from 1703 to 1712. During this period of time, Svimon stood by Vakhtang, a prolific ruler, who substantially revised the Georgian law and oversaw a series of political reforms and cultural projects.
Regency
After the death of Kaikhosro on the Afghan front in 1711, Vakhtang repaired to Isfahan to receive his investiture from ShahSultan Husayn in 1712, leaving Svimon as a regent in Kartli. Vakhtang was detained in Iran and was unable to return to his kingdom until after he had to accede to the shah's request to convert to Islam in 1716. During his tenure, Svimon continued to support Vakhtang's cultural projects, such as sponsoring the recently opened printing press in Tbilisi and, further, revived a monetary series in copper with specifically Georgian features in parallel to the standard Safavid silver coinage struck at the shah's mint in Tbilisi. In the meantime, political intrigues in Tbilisi were rife. Uncertainty over Vakhtang's prospect of returning was seen by Svimon no less than Vakhtang's other siblings—Prince Jesse and, as suspected, even the head of the Georgian Orthodox ChurchCatholicos Domentius—as an opportunity to advance their regal ambitions. Svimon arrested the catholicos and sent him for punishment to Vakhtang's son Prince Bakar, but the prelate was saved thanks to the intervention of Vakhtang's wife Rusudan. The shah was dissatisfied with Svimon, ostensibly, on account of his abuse of power. In this time of a general crisis in the country, Svimon had indeed amassed personal wealth. Another possible reason of him falling out of favor with the shah was Svimon's connection with the FrenchLazarist missionary, the abbéJean Richard, who accompanied Vakhtang's envoy Sulkhan-Saba Orbeliani in a mission to Rome and Paris, pleading for pressure on the shah to release Vakhtang.
Between Jesse and Vakhtang
The shah's plenipotentiary Kholofa, arriving in Tbilisi in 1714, successfully lobbied for more amenable Prince Jesse, a convert to Islam. Svimon also joined the endeavor and the party obtained confirmation for Jesse as king instead of Vakhtang. Relying on the Iranian support, Jesse harassed Vakhtang's immediate family and supporters. After Vakhtang at last became a Muslim, the shah, tired of Jesse's inefficient rule, confirmed Vakhtang on the throne and nominated his son Bakar regent of Kartli until Vakhtang's own return there. Bakar cast Jesse in prison and repressed his allies, but Svimon was spared. He was, further, put in command of a force, which defeated the marauding Lesgian bands in Kvemo Kartli in 1717. After Vakhtang's return to Kartli in 1719, Svimon retired from the politics and government and lived in his estate at Beshtasheni in Somkhiti. In 1723, when Constantine II of Kakheti put Tbilisi under siege, Svimon was put by Vakhtang in charge of defense of the strategic Avlabari Bridge at Tbilisi, but the prince failed in his mission and Constantine II succeeded in dislodging Vakhtang from his capital. Svimon was then with Vakhtang and Bakar in their guerrilla war and, joined by Shanshe, Duke of Ksani, attacked, unsuccessfully, Constantine's Lesgian mercenaries in the Tsilkani fortress, north of Tbilisi. Eventually, Svimon followed Vakhtang, dispossessed of his kingdom, into an exile in the Russian Empire, while Jesse once again attained to the throne of Kartli, this time under the Ottoman hegemony. Svimon, known in Russia as the tsarevich Simeon Leonovich died at the age of 56 in 1740. He was buried at the Alexander Nevsky Lavra.
Family
Svimon was married twice; he first married, in 1712, Gulkan, daughter of Bardzim, Duke of Aragvi, and then, already a widower, Ana, daughter of Prince Paata Amilakhvari. Svimon had two sons by his first marriage—Beri and Archil—and two sons by his second marriage—Stepane and Dimitri. Svimon's first wife and many of his household died in an outbreak of plague in 1717 and the prince built a church in Tbilisi in their honor. His son of the second marriage, Prince Dimitri married in Russia, in 1743, as her third husband, Princess Stepanida Rzhevskaya, former wife of Prince Aleksandr Galitzine and of Colonel Iakinf Alymov. Prince Svimon also had two natural sons—Nikoloz and Mikheil. Svimon's widow Anna filed a complaint to the Russian senate, requesting that Nikoloz, as an extramarital child, not be allowed to bear the Bagration surname. Instead, he was authorized by the Russian crown, in 1741, to have the title of prince and to henceforth call himself Prince Nikolay Semyonov. He was a dragoon officer and had a son, Fyodor. The Semyonov line has since been extinct.
