The Imperial-Royal Landwehr (German: kaiserlich-königliche Landwehr or k.k. Landwehr), also called the Austrian Landwehr, was the territorial army of the Cisleithanian or Austrian half of the Austro-Hungarian Empire from 1869 to 1918. Its counterpart was the Royal Hungarian Landwehr (k.u. Landwehr). The two Landwehrs, together with the Common Army and the Imperial and Royal Navy, made up the armed power (Bewaffnete Macht or Wehrmacht) of Austria-Hungary.
Unlike the German Empire, where the Landwehr mainly comprised reservists and volunteers, the Imperial-Royal Landwehr consisted of regular units. It was fully established with regular troops and not partly mobilized or cadred. The Landwehr should not be confused with the Landsturm which was a volunteer militia.
The roots of the Landwehr go back to the 16th century when there were calls on all able-bodied men to defend their country.
During the Napoleonic Wars a Landwehr was established by imperial decree dated 9 June 1808 as a standing and common institution to complement the regular Austrian army. This army was used in 1809 and in 1813/14. In 1859, the Landwehr was abolished.
After the Austrian Empire had lost the war against Prussia, the Kingdom of Hungary succeeding in gaining its independence from the Austria in the Austro-Hungarian Compromise in 1867. Hungary now wanted its own forces under command of the Hungarian government alongside the existing Imperial and Royal Army and Navy, which were commanded by the Emperor and Austro-Hungarian Minister of War. So the Compromise included the right of Hungary to establish the Royal Hungarian Landwehr (Kiraly Honvédség), often colloquially known as the Honved (Honvéd).