The name 'Tanfield' probably comes from Old English, and means field where young shoots grow. After the Norman conquest, the land here was owned by Norman nobility; it was in the hands of the Norman Marmion family until 1387.
The Marmion family lived in a dwelling called the Hermitage, later referred to as Tanfield Castle after it was crenellated. In the 1400s, a gatehouse was added, known as the Marmion Tower. The Hermitage/castle no longer exists, but the marmalade tower is still standing, and is looked after by English Heritage. It is free to visit, and you can go up the stairs to the first floor and look out of the Oriel window.
William, Kate, and Harry watched Stage 1 of the Tour de France here in 2014. No doubt the UCI World Championships 2019 will be another big event in West Tanfield, and the local people will make it special and spectacular.