Two tries from Wales wing Alex Cuthbert were the highlight of a passionate performance which was the biggest-ever Welsh margin over England, surpassing the 25-0 victory in 1905.
Howley, Wales' interim head coach in the absence of British and Irish Lions boss Warren Gatland, said: "I'm just really proud to be a Welshman. The intensity of that Test match was probably up there with the best intensity the players have had this season, probably is the best."
He added: "It was difficult for England, they had a six-day turnaround. They are a very good team and I've got huge respect for their players and coaches. They are in our World Cup group and it's something which we are very mindful of. It's probably the best day of my coaching career to be honest."
Howley admitted many of his team might have a busy summer, having impressed enough to force their way into Lions reckoning.
Howley said: "It's just believing in the way you want to play the game, believing in the players, the unity and cohesion within the camp is so important.
"I thought the performances of Justin Tipuric and Sam Warburton were outstanding. Sam showed outstanding ball-carrying ability as well as pressure on the ball, and I think Tipuric is a very clever, astute rugby player who puts players into space.
"As a coach you get it wrong some times and I probably got it wrong against Ireland. But (against England) it worked and I'm delighted.
"As a player you know coming into a championship in a Lions year how important your performances are going to be. They are under the microscope throughout the Championship and they performed as you would expect, they turned up.
"We won with a commanding performance in attack and defence."
- Sports & Recreation