Hull's return to the Premier League ended after a single season on Sunday, relegated after a 4-0 loss at Crystal Palace.
The result confirmed Palace's top-flight survival and ended any prospect of Swansea going down. Hull joins Sunderland and Middlesbrough in dropping into the second-tier League Championship, with the relegation places resolved ahead of the final week of the season.
"It is a sad day for the club," Hull manager Marco Silva said. "For the fans as well ... they didn't deserve what's happened with the club this season."
Hull couldn't recover from gifting Palace a third-minute goal when defender Andrea Ranocchia mistimed the ball to let in Wilfried Zaha, who slotted under goalkeeper Eldin Jakupovic. It was followed by Christian Benteke's header, Luka Milivojevic's 85th-minute penalty and Patrick van Aanholt's late strike.
Hull, who will finish 18th, had begun the season with only 13 fit senior players, without a permanent manager and amid widespread predictions of relegation. After winning only three out of 20 league games since winning promotion, Mike Phelan was fired in January. Silva was hired to stop the rot but the task was beyond the Portuguese coach.
"We did our best and we tried to do our best and we put the best team to play in the other level," Silva said. "We put the boys at the first to believe and fight until this moment. Now it is the moment to analyze."
Palace counterpart Sam Allardyce maintained his remarkable record of never having been relegated from the top flight. The 62-year-old Allardyce earned promotion with Bolton in 2001 and kept the northwest team up six times, and has since steered Blackburn, West Ham and now Palace to safety.
"I said to myself this would be the hardest one, given the quality of the teams we had to play on the run-in," Allardyce said. "The next level of the recruitment is critical to the team being more consistent and achieving more in the Premier League rather than a fight against relegation. That's something we'll discuss in the future.
"If you've got the label, you accept it (as a firefighter), but building for the future relieves the stress on you. I wouldn't want to keep fighting relegation at the end of every season. It's about building for the future."