Complex sentence: In 1600 he gained control of Moldavia, uniting the principalities of Wallachia, Moldavia and Transylvania under his rule, which lasted for a year and a half until he was murdered in 1601, by General Giorgio Basta's agents.
Split into simpler sentences: In 1600 he gained control of Moldavia, thereby uniting the principalities of Wallachia, Moldavia, and Transylvania under his rule. This lasted for a mere year and a half, until he was murdered in 1601, by general Giorgio Basta's agents.