Praeses

Praeses (Latin  "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 Nerva–Antonine dynasty. 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 "[procurator] 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.
This evolution was formalized in the reforms of Diocletian (r. 284–305) and Constantine the Great (r. 306–337), when the term "praeses" came to designate a specific class of provincial governors, the lowest after the "consulares" and the "correctores". In the East, however, they ranked between the two other classes, possibly because the few "correctores" there were instituted after the "praesides". The term "praeses" remained in general use for provincial governors, and was still used in legal parlance to designate all classes of provincial governors collectively. In common usage, the "praesides" were often also designated by more generic titles such as "iudex" ("judge"), "rector" or "moderator", and sometimes archaically as "praetor". In Greek, the term was rendered as ("hegemon").
Most of the provinces created by Diocletian by splitting the larger older ones were entrusted to such "praesides", and they form the most numerous group of governors in the late-4th century "Notitia Dignitatum":
In the East, the staff ("officium") of the "praeses" (attested for Thebais) comprised the same as that of a "consularis", i.e. a "princeps officii", "cornicularius", "commentariensis", "adiutor", "numerarius", "ab actis", "a libellis", "subadiuva"; finally unspecified "exceptores" and "cohortalini" (menial staff). In the West (attested for Dalmatia), the "officium" was again the same as with the "consulares" and "correctores", comprising the "princeps officii", "cornicularius", two "tabularii", "commentariensis", "adiutor", "ab actis", "subadiuva", and the usual "exceptores" and "cohortalini".
The status of a "praeses" could also be awarded as a separate honour, "ex praeside", attached to the rank of "vir perfectissimus".
German advisors.
In German academia a doctoral advisor is called the . However, in the 18th century and before, the doctoral system was quite different. Instead of a as such, the candidate had a "praeses" to act as mentor and who would also head the oral "viva voce" exam. In the 18th century the "praeses" often chose the subject and compiled the theses and the candidate had only to defend. Sometimes there were several candidates at the same time defending the same thesis, in order to save time.
Modern uses.
The chair of a student society in the Netherlands or Belgium may be called a praeses; in Dutch the official spelling has changed to "preses" but most student societies still observe the Latin spelling. Various minor offices may be designated by a compound title, e.g. "dooppraeses" in charge of initiation and associated hazing.
In Norway, the office of archbishop has been abolished. Instead, the Lutheran Church of Norway has a Bishops Conference which is presided over by a "praeses".
The church bodies Evangelical Church in the Rhineland and Evangelical Church of Westphalia, in which the title and function of bishop are unknown, are also chaired by a "praeses" ().
In other German church bodies the title usually refers to the president of the synod. 
Roman Catholic monastic institutions, especially Franciscan ones, use the term to indicate the presiding officer of a collegial meeting of the order.
The official Scots title of the Presiding Officer of the Scottish Parliament is "Preses o the Scots Pairlament".
The Polish word "prezes", derived from Latin "praeses" means "chairman".