Final answer:
Imam Shamil was a resistance leader against Russian expansion in the Caucasus during the 19th century, capturing the struggle of the region.
Step-by-step explanation:
Imam Shamil was a historical figure known for being a rebel against Russian encroachment into the Caucasus. He is not to be confused with Shah Ismail, who was a Safavid ruler claiming to be the Mahdi or messiah, nor related to the Crimean War during which Alexander II came into power. Imam Shamil led resistance against the Russian Empire's expansion during the 19th century but was ultimately captured in 1859 after decades of guerrilla warfare. His struggle was significant in the history of the Caucasus region and exemplifies the regional resistance against the Russian Imperial advance.