It took 24 days to sell off the 4,000 items which Horace Walpole had amassed during 50 years of avid collecting. He bought a modest property beside the Thames in Twickenham in 1749 and, by 1790, had extended and transformed it into a fairy tale summer palace where he could throw lavish parties and show off his collection to friends and visitors.

This weekend the Royal Academy (R.A) celebrates its 250th anniversary with the opening of 6 Burlington Gardens (main picture), duly refurbished for the occasion. When it was dirty the Palladian facade felt coldly overbearing, but cleaning it has highlighted the bands of sandstone and brown marble columns that lend warmth to the Portland stone. Originally built in the garden of Burlington House as the HQ for the University of London, this Victorian edifice turns out to be rather handsome. 

Henry VIII had a troubled marital history and Charles I lost his head, but both have also gone down in history as original, innovative and obsessive collectors of art, founders in different ways of what is now one of the world’s greatest accumulations in all media.

Modigliani was an addict. Booze, fags, absinthe, hash, cocaine, women. He lived fast, died young, cherished an idea of what an artist should be and pursued it to his death. His nickname, Modi, played on the idea of the artiste maudit – the figure of the artist as wretched, damned.

Annual lists of the richest, the most powerful, the movers and shakers, have an awful fascination: like gossip, we like to look and comment while feeling slightly morally compromised. But they also have a function as a snapshot of where we are at. This time it’s the turn of the art world’s most influential figures, as chosen by the magazine ArtReview, which each year creates a talking point for itself replete with embargoes and PR. 

If only a modest fuss is being made about the rare and prestigious loan currently residing in Trafalgar Square, it could be that the National Gallery is keen to forget the role of its former director, Dr Nicholas Penny, in a row about art transportation that centred on the very collection to which these objects belong.

Riveting and bewildering, the 57th Venice Biennale has just opened its myriad doors to the public with several thousand exhibits spread across Venice and its islands.

Even today, the perception of Venice as a city only half-rooted in mundane reality owes a great deal to Canaletto (1697-1768), an artist who made his name producing paintings for English tourists visiting Italy in the 18^th century. Recognisable views are subtly altered, the gently improving instincts of the artist shifting the scene almost imperceptibly away from real life, and into the realms of the imagination.

The art dealers of today must be thanking their lucky stars that Philip Hook’s remarkable history of their trade stops where it does. For while it serves as an eminently useful if rather specialised reference book, it’s a history pushed along by a ferocious analysis of the art dealing fraternity, the general thrust of which is encapsulated in its no-nonsense title. From unsophisticated third party to plutocrats’ lifestyle consultant, the evolving persona of the art dealer has taken guises ranging from merchant, scholar, connoisseur and ultimately, "purveyor of fantasy".

I avoided seeing Art when it was first staged in 1996, even though Matthew Warchus’ production created a huge buzz and won an Olivier Award for Comedy. (On receiving the award, Yasmina Reza joked that she thought she’d written a tragedy not a comedy.)