Roman Reigns currently holds the record for the longest WWE reign of the modern era which he won in WWE Payback 2020 and his reign ended in wrestlemania 40.
Brock Lesnar also known as the Beast Of WWE has a title reign of 504 days as WWE universal championship until Roman Reigns dethorned him in summer slam.
CM Punk won the WWE championship on Survivor Series 2011 and his reign ended in Royal Rumble 2013 when Rock defeated him to become new champion.
John Cena the 16 time WWE champion holds the record for 380 days which ended due to Injury.
Aj Styles defeated Jinder Mahal before the Survivor Series 2017 to become the WWE Champion and lost his Reign to Daniel Brayan after a year.
Seth Rollins cashed in his Money In The Bank contract in Wrestlemania 31 were he became WWE champion but has to vacate his title later that year due to Injury.
Drew McIntyre won the Royal Rumble 2020 and challenged Brock Lesnar for the WWE championship in Wrestlemania 36 where he became the Champion.