Iris Sharpe, who was 91, was the first chairwoman when the society was born in 1974.
The first groups to visit Aachen from Halifax went in 1949, when the heavily-bombed town needed help getting back on its feet.
Mrs Sharpe’s involvement started in 1966, when she began taking German lessons at Forest Cottage Community Centre.
Arnold Edwards, the centre’s warden, spent years organising exchanges and family holidays to Aachen, and when he retired in 1972, asked Mrs Sharpe to take over.
She recognised the need for a more formal organisation, and set up the society with the help of the council and her friends.
Her son, Tony, took over the reigns as chair in 1974.
A book published to commemorate six decades of friendship between Halifax and Aachen said of Mrs Sharpe: “Without her foresight and commitment the links might have weakened or disappeared entirely”.
In a 2009 article, Iris told the Halifax Courier she was thrilled the society continued to thrive.
“I am still in touch with friends I met years ago and I have the most wonderful memories of trips there and exchange visits between our families,” she said.
Vice-chairman of the society, Geoff Barnes, said it was to Mrs Sharpe’s credit the society continued to be a success.
“It is down to Iris being able to carry on and put it on the footing that it’s on at the present time,” he said.
Born Iris Hardcastle, she grew up in Ann Street and attended Akroyd Place School and Halifax Modern School.
In 1947 she married RAF flight mechanic Douglas Sharpe. They had two children, Susan and Tony.
Her husband died in 2007 and Tony, who worked at Shibden Hall, died suddenly in 2013.
Mrs Sharpe worked as a housing officer for Calderdale Council, and was a senior cashier at the Brighouse offices before retiring.
Mrs Sharpe lived in Northowram for most of her life but lately had been residing at Hazel Royd Nursing Home in Savile Park Road. She died peacefully in her sleep on March 2.
She also leaves a granddaughter, Rebecca, grandson Adam and four great-grandchildren.
Mrs Sharpe’s funeral is at Halifax Minster on Wednesday, April 4, at 11am, followed by a service at Park Wood Crematorium at midday.