The Streltsy were a military corps in Russia, established in the late 16th century. They served as a standing army and were primarily composed of infantry soldiers. The Streltsy played a significant role in the defense of the Russian state and were known for their use of firearms, which was relatively advanced for their time. Over the years, the Streltsy became influential in Russian politics, often participating in palace coups and uprisings. Their power peaked during the reign of Tsar Peter the Great, who eventually disbanded the corps in the early 18th century as part of his military reforms.