The world's first mechanical clock was not invented to tell the time. It was invented to regulate the sex life of the Emperor of China. In the ancient China of the Tang dynast … y, in the 8th century AD, the emperor's heir was not necessarily his firstborn son.nswered by The Community. Making the world better, one answer at a time. The first mechanical clock was made in 723 A.D. by a monk and mathematician I-Hsing. It was an astronomical clock and he called it the Water Driven Spherical Birds-Eye-View Map of The Heavens.