Six decorated and illuminated manuscripts from the Beauvais Cathedral archive are to auction at Sotheby's on July 2.

Part of the six-volume Beauvais Cathedral manuscript

Expected to bring £500,000 ($780,779) to the London sale, the six manuscripts are the last documents remaining from the great library of the cathedral chapter of Saint Peter's Beauvais.

Unseen for almost a century, the earliest volumes date from the 10th century, and were written for use in the great Roman Catholic cathedral, situated in Picardy, northern France.

A fine Romanesque manuscript boasting full-page, line-drawn illustrations is also expected to bring £500,000 ($780,779) to the London saleroom.

Still in its early medieval binding, the codex was almost certainly authored and illuminated as one of the foundation volumes of the chapel of Saint Servatius in Cologne.

Like many religious institutions in the German city, the chapel of Saint Servatius was surrendered to French revolutionary forces in 1794. The manuscript was most probably looted by French soldiers at this time and has remained in private hands ever since.

In financial terms, investing in rare books and manuscripts has more in common with opening a savings account than making a short turn investment with the aim of turning a quick profit, experienced dealer John Windle told CNBC.

"If you buy a book from me at $2,000, for you to get your money back you're going to have to wait until it's worth $4,000 and a dealer will pay you $2,000 for it. That cycle is typically about seven years."

So, while investing in rare books and manuscripts doesn't guarantee quick riches, it remains a viable way to shield yourself from market volatility, bringing both pleasure and security.

See the rare books and manuscripts we currently have in stock.

Please sign up for our free weekly newsletter.