Lazar the Hilandarian

The clock tower was located in the palace behind the Cathedral of the Annunciation. However, the clock and the church in which it was located have not survived.

• Name — Lazar the Serb • Born — mid-14th century • Birthplace — Prizren, Serbian Empire • Died — after 1404 • Field — Invention • Known for — Inventing the first mechanical clock in Russia, which was also the country's first public clock

A Serb, Lazar was born in the town of Prizren, in the Serbian Empire. He was a monk with the rank of crnorizac (chernets) serving at the Serbian Orthodox Hilandar monastery, a centre of Serbian religious and secular culture and "the first Serbian university", located on Mount Athos. Lazar likely left Mount Athos as a result of the Rise of the Ottoman Empire. 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. 1389–1425). It was the first ever spring-driven (mechanical) clock, or striking clock, in Russia, and also the country's first public clock. The clock numbers were written in Church Slavonic. It was among the first ten such advanced clocks in Europe, and was regarded a technical miracle at the time. Clocks in urban towers, or municipal hour signals, did exist earlier in Italy, though it is not known how they indicated the hours. In 1344, Paduan chronicles confirmed an entirely new technology – a clock in a tower at the Paduan palace which automatically struck the hours (24h). This hour-marker is called an hour-measure; each hour a hammer strikes the bell, measuring and counting the hours of the night and of the day... No man strikes it, but it is somehow wondrous strangely fashioned to look like a man and sound and move of itself, by man's cunning, with great invention and cleverness. The clock tower has not survived, and its exact location is undetermined, although it is believed to have been located at or near the Spasskaya Tower (formerly known as Frolovskaya). The clock was for a long time the only one in Moscow and Russia, and worked for more than two centuries without failure. It was then replaced by another clock which was destroyed in a fire. A miniature from the 16th-century Ostermanovskij manuscript (of the Litsevoy Collection of Chronicles, Ancient Chronicle, sheet 587, drawing 1175) exists which depicts the monk Lazar showing Vasily and two of his vassals the finished clock tower. Although the tower is gone, the illustration of the clock tower and monastery can be seen in the Polytechnical Museum in Moscow as of 2006. A 16th-century chronicle says that Lazar was paid 150 rubles for his work ("sta bole polutorasta rublev").

His name was Lazar (Russian and). Russian documents call him Monk Lazar the Serb (чернец Лазарь Сербии, Србин Лазар черњец). Modern sources also specifically call him Lazar the Serb (Лазар Серб), Lazar the Hilandarian and Monk Lazar.