Russia and the Caucasus 150 years ago

When Alexander I died suddenly in 1825, it was not immediately clear who would succeed to the throne. The late Czar did not have any surviving legitimate children. The eldest of his three younger brothers, Constantine, was married to a Polish commoner and secretly renounced the throne in favor of the next brother, and father to Alexander, Nicholas. The reform-minded officer class were displeased with this shift as Nicholas was known as a strict military disciplinarian.