WrestleMania is considered World Wrestling Entertainment's (WWE) flagship event, having first been held in 1985. It is the longest-running professional wrestling event in history and is held annually between mid-March to mid-April. It was the first of WWE's original four pay-per-views, which includes Royal Rumble, SummerSlam, and Survivor Series, dubbed the "Big Four". It has been described as the Super Bowl of sports entertainment. The event featured wrestlers from the Raw and SmackDown brands, and was the last under the first brand split, which ended in August. It was the last WWE pay-per-view to be promoted under the promotion's full name of World Wrestling Entertainment, as just after the event on April 7, the company began to refer to itself solely as "WWE," becoming an orphaned initialism.