Fanny Waterman, the British pianist and teacher who cofounded the prestigious Leeds International Piano Competition with Marion Harewood died Dec. 20 at a care home in Ilkley, Yorkshire. She was 100.

The idea of presenting an international music competition in 1960s Leeds, a gritty industrial city in northern England, seemed risky. But Ms. Waterman, a Leeds native, believed in the vitality of her hometown, and was certain she could draw support for the venture. The first Leeds competition took place in 1963, with the composer and conductor Arthur Bliss as chairman of an eminent jury. It was an immediate success, with 94 entrants from 23 countries.

She was appointed dame commander of the Order of the British Empire in 2005. In 2015, at 95, she retired from the Leeds Competition. “I do hope and pray,” she said at the time, “that in another 100 years, our competition will have the reputation it has now.”