始皇帝

In 221 BC 嬴政, king of 秦, finished conquering the other six states and took a new title, 皇帝, joining 皇 and 帝, words for the god-kings of legend. As the first to bear it he called himself the First Emperor. He also did away with posthumous titles, saying that sons should not judge their fathers: his heirs were simply to be numbered, and his son reigned as 秦二世, the Second Emperor.

Everyday Chinese calls him 秦始皇, 'the First Emperor of Qin'; 始皇帝 is the title itself, the form used in the histories.