Historically, the
Cerkno Hills belonged to
Tolmin County. In the 16th century, the area came under
Habsburg rule, and was included in the
County of Gorizia and Gradisca. After the end of
World War I, the area was occupied by the
Italian Army, and then officially annexed to
Italy in 1920. Between 1920 and 1943, it was part of the administrative region known as the
Julian March. After the
Italian armistice in September 1943, Cerkno was liberated by the
Yugoslav Partisans and became one of the most important centres of
Partisan resistance in the
Slovenian Littoral.
Mass grave Cerkno is the site of a
mass grave associated with the Second World War. The Lajše Mass Grave () is located south of the town, in a shaft on the edge of the woods on the eastern slope of Lajše Hill. It contains the remains of 14 civilian victims (one escaped) that were suspected of anti-communist activity and were murdered on 6 February 1944 by the
Partisans. They were killed in revenge for an attack on a Communist Party training school in Cerkno on 27 January 1944 that left 47 dead. ==Churches==