In 1808 the School of Law of the Duchy of Warsaw was founded, principally to serve the needs of the judiciary and the new administration then being established. It is this date that is conventionally taken as the beginning of the Faculty's activity. In 1811, through a merger with the School of Administrative Sciences, the two-faculty School of Law and Administration was created. Its Board of Trustees included, among others, Stanisław Staszic and Samuel B. Linde.
In 1814 the office of Dean was introduced, with the distinguished legal historian Jan Wincenty Bandtkie elected first to hold it. The School continued its work uninterrupted even during the war with Russia. Transformed by the founding charter of 1816 into the Faculty of Law and Administration, it became part of the Royal University of Warsaw, formally inaugurated on 14 May 1818.
Among the professors of the Faculty were Fryderyk Skarbek, Wacław Aleksander Maciejowski and Romuald Hube. The Faculty took an active part in the scholarly life of Warsaw — publishing the journal Themis Polska (1828–1831).
Activity was suspended during the November Uprising, and many academic staff and students took part in the fighting. As part of the post-Uprising reprisals, the University was closed on 19 November 1831. Between 1840 and 1846 only legal courses attached to the Warsaw gubernial gymnasium were permitted to function.