Taken to Russia when the pro-Persian king Rostom of Kartli defeated Teimuraz in 1648, he was raised and educated at the Romanov court at Moscow where he was known as Tsarevich Nicholas Davidovich (Russian: Царевич Николай Давыдович).

In 1662, he returned to take over the then-vacant crown of Kakheti at the invitation of local nobility, but was defeated by the rival prince Archil who enjoyed Iranian support.

Nicholas had to flee back to Russia where he featured prominently and was best man of Tsar Alexis Mikhailovich in his wedding to Natalia Naryshkina in 1671 and stood in high favor with the Russian court.

In 1674, Suleiman I asked him to decisively end his stay in Russia,[2] ordered him to Isfahan and promised to confirm him as king if Heraclius apostatized to Islam.

The khan failed, however, to prevent George XI from staging a comeback in 1691 and blockading Heraclius (Nazar Alī Khān) in Tiflis, his capital.

A vacillating ruler, addicted to strong drink, though capable at times of being brave, philanthropic and reformist, he never really achieved a firm control of his possessions, or made himself popular with the populace of Kakheti.