When Does "300" (1998) Take Place?
"300" is a historical fiction war comic-book written by Frank Miller and first released May 27th, 1998.
It takes place in the year:
480 BC
We know this because it depicts the famous and tragic Battle of Thermopylae which occurred sometime between July and October of 480 BC during the Second Persian War.
It was adapted to film in 2007.