Complex sentence: Stanisław August Thugutt (1873-1941) was a Polish activist and politician of the interwar period (Second Polish Republic), founder and leader of several peasant parties (particularly PSL Wyzwolenie).
Split into simpler sentences: Stanisław August Thugutt (1873-1941) was a Polish activist and politician during the interwar period of the (Second Polish Republic). He was the founder and leader of several peasant parties (particularly the PSL Wyzwolenie).