The origins of the Astronomical Clock remain somewhat mysterious. However, the earliest known historical reference to the clock dates back to October 9, 1410. It was installed by clockmaker Mikuláš of Kadaň and astronomer and scientist Jan Šindel. Mikuláš was granted a house near Havel’s Gate (now located near the Můstek metro station), along with a one-time payment of 3,000 groschen and an annual salary of 600 groschen for the clock’s maintenance.