London wasn't supposed to host the Games in the first place, but were offered them when Mt Vesuvius' eruption in 1906 forced Rome to drop out. Starting on April 27th, and were held in complement to the Franco-British Exhibition. In fact in early modern Games' iterations, they were usually sideshows to World's Fairs and the like. Unthinkable today, no?
Officially, there were 110 events across 22 sports. Those sports, characteristic of the Games of that era, included quaint competitions as jeu de paume (like indoor tennis), tug of war, and even power boating (the only time motorized sports were officially contested). But the sports calendar did introduce diving, field hockey, and figure skating. Yes, figure skating...that didn't move to winter until there were an actual Winter Olympics in 1924.
Finland made its debut, as did - depending on your version of records, Turkey and New Zealand. The Games were also credited as the first to position a nation versus nation format, as athletes marched in the Opening Ceremony under national flags for the first time. The organizing committee compiled the first official reports, and these Games featured the first time a marathon was officially distanced at 26miles, 385 yards.
187 days? For 110 events? Compare that to 14 days and 302 events for London in 2012. My, how a lot has changed for sure...