The eponymous wood itself is fictional, inspired by Wittenham Clumps and Wytham Woods (both near Oxford where the author was living when he wrote the first book) and borrowing its name from a village in West Sussex.
The nearness to the Iron Age hillfort of Wittenham Clumps and the Roman (and post-Roman) town of Dorchester show that the localised area was of great importance for many centuries, although the notion that Witta (and/or his family) were related to the later Royal House of Wessex, is unproven.