The First Video Game War lasted from November 21st till 1997.
King Morthophelus Koopa - October 17th 1991
Sonic's parents - December 1st 1991
Rosalina's Mother - February 1st 1992
King Dedede Sr. (Senior) - February 12th 1992
Prof. Gerald Robotnik - March 5th 1992
Maria Robotnik - May 13th 1992 (Later revived)
Mario - May 14th 1992, June 1st 1992, December 16th 1992, January 12th 1993, July 1st 1997. (Later revived)
Sonic the Hedgehog - July 17th 1992, October 30th 1992, July 1st 1997. (Later revived)
And many, many, many more.
In 1988, Sega released the Sega Genesis. When Nintendo released the Super Nintendo Entertainment System in 1990, the war unofficially began. With the release of Sonic the Hedgehog in 1991, the war officially began. When the Genesis was discontinued in 1997, the war stopped, because Nintendo had no one to fight with.