Боярин и первый сенатор Иван Алексеевич Мусин-Пушкин на службе и в кругу семьи
The paper provides new information about the biography of Ivan Musin-Pushkin, the first and lifelong Russian senator during the reign of Peter I. There is a brief summary of the author's set of arguments disproving the legend of his lineage as an illegitimate son of Tsar Alexey Mikhailovich. The reasons why the future count and senator rose through the ranks become clear, if one studies his activities during his tenure as the governor of Astrakhan and the okolnichij. The published archival documents and the letters of the count and his nearest relations help gain an insight into the prominent dignitary's character in the bosom of his family and when he was not handling nitty-gritty bureaucratic issues. Published for the first time, Ivan Musin-Pushkin's last will and testament turns out to be the quintessence of his mindset and intellectual experiences expressed in 1717.