pilgrimage church, Maria Luggau The Lesach Valley (derived from
Slavic:
les 'forest') was inhabited by
Slavs about AD 600. In the 8th century, it was one of the first valleys in the Principality of
Carantania to be
Germanised after Prince
Boruth acknowledged the overlordship of Duke
Odilo of Bavaria about 740. In 1380, the Lesach circuit (
Landgericht Lesach) was transferred to the lordship of Pittersberg, named after a nearby rock castle, then an administrative seat held by the East Tyrolean
Meinhardiner Counts of Gorizia. After their branch died out in the male line, the last countess
Margaret bequeathed the lordship to the reigning princes of the
House of Habsburg in 1363. Later it fell to the Carinthian
Counts of Ortenburg. With the creation of the
Austrian municipalities (
Ortsgemeinden) in 1850, the three municipalities Luggau, Sankt Lorenzen, and Liesing were constituted. The
cadastral communities (
Katastralgemeinden) Kornach and Strajach merged with the municipality of Mauthen, but in 1182 obtained independent status as the municipality of Unterlesach. Ten years later the two localities Birnbaum and Sankt Jakob became independent municipalities as well. Through Carinthian local government reform in 1973, the eastern Lesach municipality of Sankt Jakob merged with
Kötschach-Mauthen, while the four western municipalities were merged into the present municipality of Lesachtal. During
World War I the
Italian front between the
Austro-Hungarian Army and the
Royal Italian Army was located on the ridge of the
Carnic Alps. Many old positions and fortifications bear witness to the attritional
mountain war from 1915 to 1918. ==Population==