A pair of exceptional George Fritzsche-modelled Meissen turtle butter boxes, produced for Augustus the Strong, elector of Saxony and king of Poland, is to auction at Bonhams London on June 5.

The circa 1727-1728 butter boxes are believed to be worth �40,000-60,000 (60,000-91,000), such is their age, rarity, and the esteem in which historic German porcelain manufacturer Meissen is held.

Fit for a king: a pair of turtle-shaped Meissen butter boxes

The Meissen porcelain manufactory was founded in the early-18th century by Augustus.

Augustus' obsession with fine, imported Chinese porcelain led him to lock alchemist Johann Friedrich Bottger in a laboratory within the walls of his palace and refuse to release him until he had concocted and perfected a formula for fine bone china.

Bottger's records show that the first hard-paste European porcelain was produced in 1708.

By the time of his death in 1733, Augustus had commissioned a vast menagerie of porcelain animals, birds and figurines to people his "Porcelain Japanese Palace" in Dresden.

The present turtle butter boxes represent a tiny fraction of the 35,000 items which were produced for the king, yet since these fragile turtles were made in small quantities and possess great age, they are considered very valuable today.

A rare circa 1754 Meissen figurine entitled Cryes of London sold for $768,000 at Sotheby's in April 2007, while a pair of Meissen porcelain pugs made $548,738, also at Sotheby's, in July 2008.

May 2 saw a quantity of Meissen porcelain cross the block at Bonhams, when a distinctive Hausmaler grotesque teapot sold for $170,000.