Laibach, Congress of, conference of European powers in 1821, held in what is now Ljubljana, Slovenia. The chief powers at the congress were Russia, Austria, Prussia, France, and Great Britain. The meeting was convened to complete discussions begun at the Congress of Troppau (see Troppau, Congress of). The congress caused the breach between Great Britain and the three conservative powers of Austria, Prussia, and Russia (popularly called the Holy Alliance) to widen. Ferdinand I of the Two Sicilies was present upon invitation, and the chief action of the congress was the sanctioning of the suppression by Austrian forces of uprisings in Naples and Piedmont.