On this day in 1839, the United Kingdom captured Hong Kong as a base as it prepared for war with Qing China. The ensuing three-year conflict would later be known as the First Opium War.
This day in 1942 marked the beginning of the Battle of Stalingrad.
On this day in 1958, the Second Taiwan Strait crisis began with the People's Liberation Army's bombardment of Kinmen, an island controlled by Taiwan.
On this day in 1973, a botched bank robbery in Stockholm, Sweden, turned into a hostage crisis; over the next five days the hostages began to sympathize with their captors, leading to the term "Stockholm syndrome".
And on this day in 2011, Libyan leader Muammar Gaddafi was overthrown.