By 1905 Baku was producing around 50% of the world’s petroleum and immensely rich “oil barons” built luxurious mansions outside the walls of the increasingly irrelevant Old City. Meanwhile, most oil workers lived in appalling conditions, making Baku a hotbed of labor unrest and revolutionary talk.
In the early 18th century, a collection of autonomous Muslim khanates emerged across Azerbaijan. However, to preserve their independence against a rebounding Persia, several khanates united and asked Russia for assistance. They got more than they bargained for. The Russian Empire swiftly annexed many northerly khanates.
Nonetheless, realization of Baku’s potential vulnerability encouraged Soviet engineers to develop new oil fields in distant Siberia after the war.
On 20 January 1990, the Red Army made a crassly heavy-handed intervention in Baku, killing dozens of civilians and turning public opinion squarely against Russia.