Heather Watson and Henri Kontinen won the mixed doubles as Watson became the fourth British player to secure a title on Wimbledon's final day.
Finn Kontinen and Guernsey's Watson beat Colombian Robert Farah and Anna-Lena Gronefeld of Germany 7-6 (7-5) 6-4 after Andy Murray won the men's final.
"I can't stop smiling. I just can't describe how happy I am," Watson said.
The British number two had never before progressed beyond the third round of a Grand Slam, while she and Kontinen only played together for the first time last week.
They were unseeded and beat defending champions Leander Paes and Martina Hingis in the third round before defeating 15th seeds Farah and Gronefeld to claim the final title of the championship on centre court.
The last time two Brits won two of the five traditional titles at Wimbledon (the men's and women's singles and doubles plus the mixed doubles) was in 1937, when Dorothy Round Little won the women's singles and Billie Yorke teamed up with France's Simonne Mathieu to win the women's doubles.
"We gelled straight away," Watson told BBC Sport.
"I couldn't have picked anybody better to share this experience with than Henri. We just had so much fun and that's why we played well together.
"We all want to win but it is important to enjoy it. Our personalities are pretty laid back, and we like to have a good time. [To Kontinen] Thanks for putting up with me."
Watson suffered "one of the worst" defeats of her career when losing to Annika Beck in the first round of the singles, failing to convert three match points in the deciding set.
In claiming victory on Sunday she became the first British woman to win a Wimbledon doubles title since Jo Durie in 1987, who that year won the mixed doubles with Jeremy Bates.
"After such a horrible first-round loss, I made it to the last day of Wimbledon," Watson added.
"It's been a dream of mine since I was a little girl to be a Grand Slam champion. I would take anything, singles, doubles, mixed doubles. Yeah, I've got one of those now."
Sam Smith, former British number one on BBC TV:
"Heather and Henri: Never say never, you will go to the ball.
"Watson played brilliantly throughout this event, and they gelled wonderfully. There's a lovely chemistry between them and this could be a real springboard for the both of them. What a way to end the championships."