Complex sentence: After the sign of the treaty of 1350, Bolko II began the process of approaching to the House of Luxembourg, but without sacrificing his good relations with the Kings Casimir III of Poland and Louis I of Hungary.
Split into simpler sentences: After the signing of the treaty of 1350, Bolko II began the process of rapprochement with the House of Luxembourg. This was done without sacrificing his good relations with the Kings Casimir III of Poland and Louis I of Hungary.