When tax adviser Will Gull, 30, spotted pretty teacher Katie Crammer, 27, getting on the tube at Bank station in December 2006, he couldn't resist.
"I think you are beautiful, from Will," he wrote, scribbling his phone number on a note he passed to Katie, who is Jewish.
The pair got off the train at South Woodford station and three years later Will proposed on the station platform, in front of commuters and station staff.
This week the newly-married couple travelled back to South Woodford. Katie, from Buckhurst Hill, said: "I am very grateful to London Underground." Who said romance was dead?