Prince of Moldavia. The heir's new wife soon became involved in court intrigues, especially after 10 October 1483, when she gave birth to a son, Dmitry. After the annexation of Tver in 1485, the Grand Duke named Ivan the Young Grand Prince of this domain. During the 1480s, Ivan's position as the rightful heir was quite secure and Sophia's supporters became less so. In particular, the Grand Princess was unable to obtain government posts for her relatives: Her brother, Andreas, departed from Moscow with nothing, and her niece, Maria (wife of Vasily Mikhailovich, Hereditary Prince of Verey-Belozersky), was forced to flee to Lithuania with her husband, an event that further undermined Sophia's position at court. According to sources, Sophia had arranged her niece's marriage to Prince Vasily in 1480, and in 1483 she gave Maria some jewelry that belonged to Ivan III's first wife. When Ivan the Young asked for these jewels (he wanted to give them to his wife, Elena, as a gift), he discovered they were missing. Outraged, he ordered a search. Prince Vasily did not wait for retribution, but fled to Lithuania with his wife. One direct consequence of this episode was that Prince Michael of Verey-Belozersky, Vasily's father, bequeathed his domains to the Grand Prince, effectively disinheriting his son. Sophia was able to obtain a pardon for her niece and her husband in 1493, but they never returned. New factors came into play around 1490 when Ivan the Young became ill. The diagnosis was gout. Sophia wrote to a Venetian doctor named Leon, who imprudently promised Ivan III that he could cure the heir to the throne. All efforts failed. Ivan the Young died on 7 March 1490, and the doctor was executed. Rumors spread through Moscow that Sophia had poisoned the heir. Andrey Kurbsky, who wrote about these events almost 100 years later, said that these rumors were indisputable facts. However, modern historians say that, due to lack of sources, the theory that Sophia poisoned Ivan the Young cannot be verified. In 1497, Sophia and her eldest son, Vasili, were allegedly involved in a plot to kill Prince Dmitry, son of Ivan the Young. Both were disgraced and probably banished from court. On 4 February 1498, in the Dormition Cathedral in an atmosphere of great splendor, Prince Dmitry was crowned Grand Prince and co-ruler with his grandfather. Sophia and her son Vasili were not invited