 Complete the following phrase:  By the 18th century, the Russian Empire extended its control to the Pacific, peacefully forming a common border with the Qing Empire and Empire of Japan. This took place in a large number of military invasions of the lands east, west, and south of it. The PolishRussian War of 1792 took place after Polish nobility from the PolishLithuanian Commonwealth wrote the Constitution of 3 May 1791. The war resulted in eastern Poland being conquered by Imperial Russia as a colony until 1918. The southern campaigns involved a series of Russo-Persian Wars, which began with the Persian Expedition of 1796, resulting in the acquisition of Georgia country as a protectorate. Between 1800 and 1864, Imperial armies invaded south in the Russian conquest of the Caucasus, the Murid War, and the Russo-Circassian War. This last conflict led to the ethnic cleansing of Circassians from their lands. The 