The
Illyrian movement (, ) was a pan-
South-Slavist cultural and political campaign with roots in the
early modern period, and revived by a group of young
Croatian intellectuals during the first half of the 19th century, around the years of 1835–1849 (there is some disagreement regarding the official dates). This movement aimed to create a Croatian national establishment in
Austria-Hungary through linguistic and ethnic unity, and through it lay the foundation for cultural and linguistic unification of all
South Slavs under the revived umbrella term
Illyrian.