Tietse Pieter Sevensma (22 July 1879 â 30 June 1966) was a Dutch theologian, political scientist, author, editor, encyclopedist and international librarian.
Born in Sneek, Frisia, the Netherlands, Sevensma studied theology and later political science in Amsterdam. After completing his modernist doctoral thesis on the Jewish ark (De ark Gods, het Oud-Israëlitisch heiligdom, 1908) he studied political science (Staatswetenschappen) but then took to establishing libraries, at the Rotterdam Nederlandsche Handels-Hoogeschool (Rotterdam business school, the forerunner of Erasmus University) from 1908 up to 1916, and the Amsterdam public reading room as a director since 1916, where he added a library for the blind and sheet music. In 1912 he was a co-founder of the Dutch national librarian society (Nederlandse Vereniging van Bibliothecarissen, NVB) and served as its first president from 1912 - 1923.
Sevensma was editor-in-chief of the Dutch encyclopedias Zoek-licht, Nederlandsche encyclopædie voor allen (1922âÂÂ1925, 1931, 9 volumes), Het nieuwe zoeklicht, Nederlandse encyclopædie voor allen (1941, 4 volumes), and Zoek-licht encyclopedie. Vraagbaak voor Noord- en Zuid-Nederland in tien delen (1956âÂÂ1960, 10 volumes, with G. Schmook).
Since 1924 he also directed and reorganised the University of Amsterdam library. A next career step brought him to Switzerland: between 1928 and 1938 he led the League of Nations Library at Geneva and rebuilt it there using a donation from John D. Rockefeller Jr. starting in 1930, as it still stands as of 2025 as the United Nations Library and Archives building. In 1929, Sevensma was appointed Secretary General of the International Federation of Library Associations, a post he held until 1958.
In 1938, Sevensma returned to the Netherlands to be Librarian of Leiden University up to 1947. In 1939 he bought Willem de Vreese's Bibliotheca Neerlandica Manuscripta, a documentation system of Middle Dutch manuscripts. During the Second World War the Leiden university library remained open, but the university was closed on 27 November 1940 on the orders of the German occupying authorities, after the protest of professor Rudolph Cleveringa against the obligatory firing of 37 Jewish university personnel, including two library assistants who were later murdered by the Germans. Sevensma successfully protected the Leiden library inventory of manuscripts against predatory despoliation by German librarians.