Measuring 21½ft (6.5m) long and written in Anglo-Norman French, the roll comprises nine pieces of parchment glued end to end.
It is not the first time the map has appeared on the market – it was sold by the Chaworth Musters family in 1988 after six centuries with the family and then offered by London gallery Sam Fogg in 2005.
However, the topographical importance of the map is a recent discovery. A pictorial preface depicts the royal roads of England, part of a mild programme of propaganda on the scroll justifying royal authority through geography, fate and history.
It is thought to have been commissioned by Sir Thomas Chaworth for his children (scrolls of this type were often used as educational tools) and traces the royal pedigree of the line from Egbert (r.802-829) to Edward II (r.1307-27) with a later extension including Henry IV. Each monarch’s reign is summarised in a pithy burst of text.
Only about 30 such genealogies are known to have survived. The Chaworth Roll is similar in style and content to three others, one in the Bodleian Library, Oxford and two in the Cambridge University Library, though it is better condition. The existence of the other map suggests that Sir Thomas may have commissioned one scroll for each of his four children.
It is on offer from Daniel Crouch Rare Books for £750,000. TEFAF Maastricht runs until June 30.