The rivalry between the two promotions pushed them to create exciting shows, watched in front of sold-out arenas and millions at home. The competition also helped in building and shaping future pro wrestling legends.
While WWE was building new stars, WCW depended on legends of the pro wrestling business, many of whom had left WWE for WCW. Some future WWE Superstars had brief stints in WCW, before it was bought by WCW in 2001.
Here, we take a look at 6 current WWE Superstars you forgot were in WCW:
#6 Charlotte Flair
Charlotte Flair has carved a legacy for herself in WWE as one of the most important Superstars in the women's evolution. The daughter of the legendary Ric Flair, Charlotte wasn't even interested in pro wrestling a decade ago. She only signed with WWE in 2012, but quickly got to grips with the wrestling business, debuting a year later.
Flair, though, had been in pro wrestling over a decade earlier, as part of a storyline featuring her father Ric Flair, in his feud with Vince Russo and her brother, David. Charlotte, who went by her real name Ashley when she was in WCW, was just 14 when she was first seen in the promotion.
She featured alongside her father and mother in various vignettes and was also ringside for her father's match against David Flair.
Although both her brothers, David and the late Reid, wrestled, with the former featuring prominently in WCW, Charlotte did not wrestle until signing for WWE. Now she is a multi-time women's champion, winning the RAW, SmackDown, NXT and Divas Championships in WWE.