The Manuel March collection will be auctioned at Christie's tomorrow and Thursday (October 28-29) and is composed of 500 lots.
These include silver and furniture pieces, but mostly represent the core of a great 20th century collection of art.
Some of the highlights include a collaborative painting, circa 1655, of Saint Teresa of Ávilagarlanded with flowers, estimated at £40,000-60,000.
Intriguingly, the flowers splayed above the saint appear to have been painted by Jan Philips van Thielen, while a fruit bowl before her seems to have been painted by van Thielen's contemporary Joris van Son. The figure herself may not have been painted by either of them.
A great John Singer Sargent work included in the sale, circa 1909, is a landscape of Mallorca in pencil and watercolour featuring a view of a rocky ridge above the sea. It is valued at £120,000-180,000.
Sargent turned to watercolour landscapes when he had grown tired of the restrictions of portrait painting. In this piece, he aims to capture the effect of direct sunlight on rock, and the hazy view in the distance on a hot day.
"Sargent's watercolours obey the requirement of art in the most important way: they remain fresh forever, they endure", commented Donelson F Hoopes in his book on Sargent's works.
A remarkable piece of jewellery by Fabergé will also appear in the sale, a jewelled, enamelled gold cigarette-case estimated at £20,000-30,000.
The 8.6cm long box features bands of white enamel with red, green and white berry and leaf enamel borders. The hinge clasp is made of rose diamond.
Among the furniture highlights is an octagonal mahogany table, thought to be the work of Marsh and Tatham which is expected to sell for up to £100,000.
Finally, the top lot is by Joaquin Mir i Trinxet (1873-1940), who was one of a group of Catalan artists known as the Colour of Saffron. The group painted landscapes in the countryside near Barcelona, and have been recognised as particularly innovative and free-styling in their use of colour.
An oil painting of Tarragona by Trinxet is here valued at £150,000-£250,000.