Алексей is a common male name in Russia and other Slavic countries. It is derived from the Greek name "Alexios," meaning "defender" or "helper." The name has been popular throughout history and is often associated with various notable figures, including saints and historical leaders. In modern times, many people named Алексей have made significant contributions in various fields, such as science, literature, and politics. The name is often shortened to "Леша" in informal settings. It remains a popular choice for parents naming their sons in Russia and neighboring countries.