LTReikšminiai žodžiai: Federacija; Antroji Lenkijos Respublika; Pilsudskis; Lietuva; Baltarusija; Ukraina. Keywords: Federation; Second Polish Republic; Pilsudski; Lithuania; Belarus; Ukraine.
ENThe article presents federation concepts formulated in the Second Polish Republic, their origins, goals, principles, and justifi cation. It briefl y discusses the political circles in which they were thought out. Left -wing groups predominated, with socialists being particularly active in this fi eld. Th eir authors referred to the Jagiellonian tradition and the Polish-Lithuanian Commonwealth, and promoted the idea of a trialist federation consisting of Poland, Lithuania, and Belarus. Less frequently, the concepts included Ukraine and other Baltic states, such as Latvia and Estonia. Aft er the Riga Treaty of 1921, federation concepts were defi ned only sporadically.