His last, and perhaps the most momentous act, was his will and testament known as "The Succession Statute" in which he divided the country among his sons, leading to almost 200 years of feudal fragmentation of the Polish Kingdom.
Tindakan terakhirnya diduga adalah tindakannya yang paling penting, yaitu wasiatnya yang dikenal sebagai "Undang-undang Suksesi" dimana ia membagi negara di antara putra-putranya, yang mengarah ke fragmentasi feodal Kerajaan Polandia selama hampir 200 tahun.