Praeses
Praeses (Latin pl. praesides) is a Latin word meaning "placed before" or "at the head". In antiquity, notably under the Roman Dominate, it was used to refer to Roman governors; it continues to see some use for various modern positions.
Roman governors
Praeses began to be used as a generic description for provincial governors—often through paraphrases, such as qui praeest ("he who presides")—already since the early Principate, but came in general use under the Antonines. The jurist Aemilius Macer, who wrote at the time of Caracalla (reigned 198–217), insists that the term was applied only to the governors who were also senators—thereby excluding the equestrian procuratores—but, while this may reflect earlier usage, it was certainly no longer the case by the time he wrote. In the usage of the 2nd and 3rd centuries, the term appears originally to have been used as an honorific, affixed to the formal gubernatorial titles (legatus Augusti etc.), and even, occasionally, for legion commanders or fiscal procuratores. By the mid-3rd century, however, praeses had become an official term, including for equestrian officials. The form vice praesidis had also come into common use for equestrian procuratores entrusted with the governance of provinces in the absence of, or in lieu of, the regular (senatorial) governor. This marks a decisive step in the assumption of full provincial governorships by equestrians, with the first equestrian praesides provinciae appearing in the 270s.