Praeses (plural Praesides), is a Latin word meaning "Seated in front of, i.e. at the head (of a meeting or company)", has both ancient and modern uses.
Roman imperial use 
Praeses, a common Latin word, meaning chief or patron, was increasingly used for Roman governors during the 2nd century AD, largely replacing procurator. When Diocletian remodeled the system at the end of the 3rd century, he reduced the sizes of the provinces and called all provincial governors praesides. He also made it impossible for Roman Senators to be governors, restricting the office entirely to the equites (knights). In the 6th Century, when Justinian increasingly reversed Diocletian's strict separation of civil and military authority, praeses granted military authority over their province were generally elevated to the related, older term Praetor.
Provinces administered by a Praeses 
There were thirty-one provincial praesides in the Western Roman Empire:
- four in Illyricum: Dalmatia, Pannonia Prima, Noricum mediterraneum, Noricum ripense
- seven in Italia: Alpes Cottiae, Rhaetia Prima and Secunda, Samnium, Valeria, Sardinia, Corsica.
- two in Africa: Mauretania Sitifensis, Tripolitana
- four in Hispania: Tarraconensis, Carthaginensis, Mauretania Tingitana, Insulae Baleares
- eleven in Gallia: Alpes Maritimae, Alpes Poenninae et Graiae, Maxima Sequanorum, Aquitanica Prima and Secunda, Novempopulana, Narbonensis Prima and Secunda, Lugdunensis Secunda, Tertia and Senonica
- three in Britannia: Britannia Prima and Secunda, Flavia Caesariensis.
There were forty provincial praesides in the Eastern Roman Empire:
- five in Egypt: Libya Superior and Inferior, Thebais, Ægyptus, Arcadia.
- eight in Oriens: Palaestina Salutaris and Secunda, Phoenice Libanensis, Euphratensis, Syria Salutaris, Osrhoene, Mesopotamia, Cilicia Secunda
- seven in Asiana: Pisidia, Lycaonia, Phrygia Pacatiana and Salutaris, Lycia, Caria, Insulae.
- eight in Pontica: Honorias, Cappadocia Prima and Secunda, Helenopontus, Pontus Polemoniacus, Armenia Prima and Secunda, Galatia Salutaris.
- four in Thracia: Haemimontus, Rhodope, Moesia Secunda, Scythia
- four in Dacia: Dacia ripensis, Moesia Prima, Praevalitana, Dardania
- four in Macedonia:Thessalia, Epirus vetus and nova, Macedonia salutaris.
Old German academic use 
In German academia a doctoral advisor is called the Doktorvater. However in the 18th century and before, the doctoral system was quite different. Instead of a Doktorvater, 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 use 
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 be a compound title, e.g. dooppraeses in charge of initiation and associated hazing.
In Norway, the office of archbishop has been abolished. Instead, the Church of Norway has a Bishop’s Conference which is presided over by a praeses which is elected for four years. Also the church bodies Evangelical Church in the Rhineland and Evangelical Church of Westphalia, which do not know the title and function of bishop, are chaired by a praeses (German: Präses, plural: Präsides). In other German church bodies the title usually refers to the president of the synod.
See also 
- Cassell's Latin Dictionary.
- Oxford Classical Dictionary s. "procurator"