Easter as Christ's resurrection day...how did it start?

The feast day of Easter was originally a pagan celebration of renewal and rebirth. Celebrated in the early spring, it honored the pagan Saxon goddess Eastre. When the early missionaries converted the Saxons to Christianity, the holiday, since it fell around the same time as the traditional memorial of Christ’s resurrection from the dead, was merged with the pagan celebration, and became know as Easter

Source:
http://matthewzavoras.wordpress.com/2011/04/24/the-meaning-of-easter-jesus-christs-resurrection/