1827 to 1960 and is located in the main library. The building The main library is housed in a building from 1917 designed by architect Erik Lallerstedt, who also designed the rest of the university's then new campus. The building was later rebuilt several times, and in the 1950s the former open courtyard was built in. During the period 2000–2002, the building was rebuilt according to drawings by architect Per Ahrbom. The extension from the 1950s was demolished and a new entrance and office building with a glass facade were erected. The courtyard is the library's central room, and the rest of the library is grouped around the courtyard. Old facades have been renovated, both towards the courtyard and towards the streets. Inside, the old part of the house has been renovated and regained much of the original architecture. The renovation and extension of the library has won several architectural awards. In 2004, Per Ahrbom was awarded the “Helgopriset”. Directors The title was överdirektor first, then föreståndare and from the beginning of the 20th century rektor. For Teknologiska institutet 1825–1845: 1845–1848: , (acting) 1848–1855: 1856–1877(1890): For KTH (1856)1877–1890: 1890–1902: (acting) 1902–1909: Anders Lindstedt 1909–1922: 1922–1927: 1927–1931: 1931–1943: Henrik Kreüger 1942: , (acting) 1943–1964: 1964–1968: 1968–1974: 1974–1980: 1980–1988: 1988–1998: 1998–2007: Anders Flodström 2007: 2007-2016: 2016-2022: Sigbritt Karlsson 2022 -: Anders Söderholm Notable alumni Many prominent former students have attended KTH, including; Immanuel Nobel, inventor and industrialist Salomon August Andrée, Arctic explorer Gustaf Larson, co-founder of Volvo Niklas Zennström, co-founder of Skype Ernst Alexanderson, inventor Joe Armstrong, creator of the programming language Erlang Kurt Atterberg, composer (graduated 1911) Peter Arvai, CEO and co-founder of Prezi, graduated 2006 Karl-Birger Blomdahl, composer Samir Brikho, chief executive of AMEC Georg Theodor von Chiewitz, architect Magnus Egerstedt, professor at Georgia Institute of Technology Daniel Ek, entrepreneur and technologist who started Spotify (did not graduate) Börje Ekholm, previously CEO of Investor AB and after that CEO of Ericsson AB Carl Daniel Ekman, pioneer in producing wood pulp for paper Erik Engstrom, chief executive of Reed Elsevier Knut Frænkel, Arctic explorer Christer Fuglesang, ESA astronaut, first Swedish citizen in space, physicist Ali Ghodsi, co-founder and CEO of Databricks Ivar Jacobson, inventor of sequence diagrams, and Unified Modeling Language (UML) Ivar Kreuger, industrialist Almida de Val, Olympian Peter Lindgren, former guitarist of Opeth Fredrik Ljungström, inventor, KTH Great Prize recipient Emma Lundberg, cell biologist, professor at KTH Royal Institute