Praetor (fvillha in the Romulan language) was a title held by a Romulan judicial official with executive governmental powers. This leader was chosen by the Imperial Senate of the Romulan Star Empire. During the expansion of the Romulan Star Empire, the influence of the Praetor of the Romulan Star Empire became much expanded, yielding substantial control over the Romulan Senate and the Romulan Star Navy, and even having a separate military force, the Praetorian Guard. (TOS - Rihannsu novel: The Romulan Way. ST reference: Federation: The First 150 Years)
The Praetor gained expanded powers and removed powers of the Imperial Senate that made him a dictator by the 2100s. ST reference: Federation: The First 150 Years)
By the year 2387, the title of Praetor was also used to refer to the leader of the Vulcan High Command. (ST - Countdown comic: "Number One")