My ingredients for a perfect day out, in no particular order, are historic buildings and gardens, bookshops and tea shops. The town of Alnwick in Northumberland offers all these and more. Alnwick Castle has been in the hands of the Percy family since the fourteenth century, when they acquired it from the Bishop of Durham, Antony Bek in 1309. The castle he bought was a typical motte and bailey castle. The showpiece and popular filming location you can see today is the product of many adaptations over the centuries, with the impressive state rooms lavishly redesigned in an Italianate style in the nineteenth century.

It’s an impressive sight, but as a medievalist I am intrigued by the story of how the bishop came to acquire it from William de Vesci, the last Vesci lord of Alnwick, who had no surviving legitimate son. At the time, the bishop of Durham was…