An illuminated 14th century manuscript containing what is believed to be the oldest surviving account of the legends of King Arthur is to be sold for up to £2 million.

The Rochefoucauld Grail, a colourful, illustrated account of the knights of the round table, Merlin and the Holy Grail is said to be one of the finest mediaeval texts in private hands.

It is due to be sold by auction house Sotheby’s in London for a price estimated between £1.5 million and £2 million.

More than 200 cows would have been needed to produce the vellum sheets for the three hefty volumes of the manuscript, which contains 107 finely painted illustrations.

It was written in Flanders or Artois some time between 1315 and 1323 and probably produced for Guy VII, Baron de Rochefoucauld, head of one of the leading aristocratic families of medieval France.

The manuscript went on to be acquired by 19th century collector Sir Thomas Phillipps and has changed hands twice since.

The stories of Arthur, the lady in the lake and Lancelot which it contained were popular in their day and were translated widely around Europe, and became something of a guidebook for chivalry.

Sotheby’s specialist Dr Timothy Bolton said: “This is one of the principal manuscripts of the first significant medieval work of secular literature.

“It is a grand book, in a monumental format, with 107 miniatures, each a dazzling jewel of early gothic illumination. “The scenes often have a riotous energy, and often stretch beyond the boundaries of the picture frames, with lofty towers poking through the borders at the top, and figures tumbling out of the miniatures onto the blank page as they fall or scramble to escape their enemies.”

The manuscript is due to be sold at Sotheby’s sale of western manuscripts and miniatures on December 7.