1404), was a Serbian Orthodox monk-scribe and horologist who invented and built the first known mechanical public clock in Russia in 1404.

Prior to his arrival in Moscow, Lazar had served as a monk in the Serbian Hilandar monastery at Mount Athos.

[5][6] Russian chronicles speak of Lazar, newly arrived from Serbia, inventing and building a clock on a tower in the Grand Prince's palace in Moscow behind the Cathedral of the Annunciation at the request of Vasily I, the Grand Prince of Moscow (r.

[19][20] The Serbian Orthodox Church decided to celebrate the 600th anniversary of the monk Lazar's invention and construction of the great clock tower in the Moscow Kremlin on the feast of the Presentation of Mary (Ваведење) on 4 December 2004.

The liturgies of the churches in Belgrade and Moscow, the Hilandar (where the brotherhood had their krsna slava) and the Monastery of the Holy Archangels, mentioned Lazar.

He had to have knowledge of Archimedes' division of circuit tracks and estimation of the extent to forge three types of gear wheels.

Часовников механизъм с ...In the year 1404 a monk from the Mons Athos named Lazar, a born Serb, made in Moscow, at the court of the great duke Vasilij Dimitrović, the first tower clock which struck hoursA mechanical tower clock appeared in Russia in 1404 during the reign of Prince Vasilii Dmitrievich, son of Dmitrii of Don.

(1404) veliki knez (Vasilij Prvi) naumi časnik (časovnik) i postavi ga na svome dvoru kod crkve Sv.