The Dark Days

Approximately seventy-four years before the events of The Hunger Games  the various districts of Panem rebelled against the Capitol.

The Capitol claims that for every dead Capitol citizen, two rebels died), but by the end of the conflict, the Capitol had quelled the rebellion, defeating twelve of the districts and obliterating the thirteenth entirely.

The Hunger Games
In the wake of the rebellion, the Capitol established the Hunger Games, an annual event in which twenty-four children between the ages of twelve and eighteen, one boy and one girl from each district, are chosen
The event served two purposes. The first was to demonstrate the overwhelming power the Capitol had over the districts The second purpose was purely for entertainment.
The Hunger Games are a nationally televised event in the same vein as a reality show.