Complex sentence: During 966-1018,1340-1772 and during 1918-1939 Sianky was a part of Poland, while during 1772-1918 it belonged to Austrian empire (later Austrian-Hungarian empire when double monarchy was introduced in Austria).
Split into simpler sentences: During 966-1018,1340-1772 and during 1918-1939 Sianky was part of Poland. While during 1772-1918 it belonged to Austrian empire (later Austrian-Hungarian empire when double monarchy was introduced in Austria).