The word prothonotary is recorded in English since 1447, as "principal clerk of a court," from L.L. prothonotarius (c. 400), from Greek protonotarios "first scribe," originally the chief of the college of recorders of the court of the Byzantine Empire, from Greek πρῶτος protos "first" + Latin notarius ("notary"); the -h- appeared in Medieval Latin. The title was awarded to certain high-ranking notaries.
Byzantine usage 
The office of prōtonotarios (Greek: πρωτονοτάριος), also proedros or primikērios of the notarioi, existed in mid-Byzantine (7th through 10th centuries) administration as head of the colleges of the notarioi in various administrative departments. There were prōtonotarioi of the imperial notarioi (secretaries of the court), of the various sekreta or logothesia (government ministries), as well as for each thema or province. The latter appeared in the early 9th century and functioned as the chief civil officials of the province, directly below the governing general (stratēgos). They were responsible chiefly for administrative and fiscal affairs (characteristically, they belonged to the financial ministry of the Sakellion), and were also responsible for the provisioning of the thematic armies. The office vanished after the 11th and 12th centuries, along with the themata and the logothesia, although there are traces of a single prōtonotarios functioning as the emperor's chief secretary until the Palaiologan period.
Catholic Church usage 
In the Roman Catholic Church, protonotaries apostolic (Latin protonotarii apostolicii) are prelates in the Roman Curia who perform certain duties with regard to papal documents. Also, after examining the candidates, they name annually a fixed number of doctors of theology and canon law. Historically, the college of protonotaries developed out of the seven regional notaries of Roman antiquity, and are therefore called protonotaries de numero (of the number). They are also called "participating" protonotaries, because they shared in the revenues as officials of the Roman Chancery.
These high papal officials are the highest class of Monsignor, are often raised directly to the cardinalate, and hold distinctive privileges in address and attire. Current practice is based on Pope Paul VI's two motu proprios, Pontificalis Domus of March 28, 1968 and Pontificalia Insignia of June 21, 1968. They are addressed formally as "most reverend monsignor," and they wear the mantelletta, the purple choir cassock, the biretta with red tuft, and rochet for liturgical services, the black cassock with red piping and purple sash at other times, and may add the purple ferraiuolo to the black cassock for formal ceremonies of a non-liturgical nature, e.g., a graduation.
There are also honorary protonotaries, referred to as supernumerary (or 'beyond the number'), on whom the pope has conferred this title and its special privileges. This title is purely honorary and is not attached to any duties in the Curia. This is the type of protonotary found outside of Rome, and is the highest grade of monsignor found in most dioceses. Priests so honored are addressed as "reverend monsignor", wear the purple choir cassock (with surplice) for liturgical services, the black cassock with red piping and purple sash at other times, may add the purple ferraiuolo to this for formal non-liturgical ceremonies, and may put the letters "P.A." after their names, but use none of the other accoutrements mentioned above.
Secular judiciary 
In the Federal Court (Canada), the Prothonotary is not a clerk, but instead is a judicial officer appointed under the Federal Courts Act and exercises many of the powers and functions of a Federal Court Judge. The Prothonotary's authority includes mediation, case management, practice motions (including those that may result in a final disposition of the case, regardless of the amount in issue), as well as trials of actions in which up to $50,000 is claimed (see Rules 50, 382, and 383 to 387 of the Federal Courts Rules). The current members of the Court are found at Prothonotaries.
Chief court clerk 
The prothonotary is the chief court clerk in certain courts of law in certain Anglo-American jurisdictions, including the American states of Pennsylvania and Delaware, the Canadian provinces of Nova Scotia and Prince Edward Island, and the Supreme Courts of the Australian states of New South Wales and Victoria.
The Prothonotary of the Victorian Supreme Court has responsibility for all administrative tasks of the trial division registry. Under the Supreme Court Act 1986 (Vic), and the accompanying rules, the Prothonotary also has some quasi-judicial powers including taxation of costs, conducting mediations, prosecuting contempt and administering bail.
Much of the work of the Prothonotary is delegated to specifically appointed Deputy Prothonotaries who, under the Supreme Court Act (s108), have the same powers and authority as the Prothonotary.
U.S. President Harry S Truman was introduced to a prothonotary during a campaign stop in Pittsburgh in 1948. It is widely rumored that Truman's first reaction upon hearing the term "prothonotary" was to say "What the hell is a prothonotary?" Truman is also attributed with saying that "prothonotary" was the most impressive-sounding political title in the U.S.
- * Kazhdan, Alexander, ed. (1991). Oxford Dictionary of Byzantium. Oxford University Press. p. 1746. ISBN 978-0-19-504652-6.
- The story about Harry S Truman is repeated in:
- David M. Brown. (April 3, 2005). Lamb Says City Should Change How it Does Business. Pittsburgh Tribune-Review. Accessed 2006-11-14.
- Jon Delano. (March 14, 2003). Row Office Holders Not Political Bumpkins. Pittsburgh Business Times. Accessed 2006-11-14.
- Peacock Keller. (July, 2005). What's a Prothonotary?. Accessed 2006-11-14.
- Jerome L. Sherman. (May 18, 2005). 6 Elected Row Officers Become 3 Appointed. Pittsburgh Post-Gazette. Accessed 2006-11-14.