Well done Mr. Fox - was waiting for someone else to bring that bit of info up about Sickert. I've debunked enough already.
As you say Cornwell IS a cultural vandal who is a firm propoent of the adage "Never let the truth get in the way of a good story". Another is Dan Brown.
Am just reading a booklet quantifying the mistakes and outright screw ups he claims as fact in the Da Vinci Code: simple things like being driven from his hotel to the Louvre via the Opers House inParis when to do that means you are exchanging a pleasant 250 metre stroll for a 10 minute-plus carjourney that initially takes you AWAY from the Louvre before turning back on your tracks to return to it!! All the way up to using discredited information - like his stuff about Rosslyn Chapel (ALL wrong) and even to the point of placing incorrect artists in certain galleries at the Louvre and just who happens to be whom in certain paintings. He can't even have his 'heroes' catch the correct train from the correct station at the coprrect time - he puts them on a train leaving Gare St.Lazaire at about 3am and the that train leaves Gare du Nord at 11pm - it's the last one.
Even his London info is crap - most of it is wrong: EG you cannot see Westminster Abbey from thee Horse Guards Parade Ground as Brown has his hero manage, The Inquisition did NOT execute over 5,000,000 witches during its reign of terror - estimates range between 40 and 60 THOUSAND killed. While this is a lot - it's also a LOT LESS than 5 million !!!!

Bottom line - both are simply authors and both make the mistake of attempting to con their readers that their research and information are TRUE FACT - truth be told - - - THEY'RE NOT! They are both just STORIES which is why we buy them from the FICTION SHELVES of bookshops. Neither Cornwell's book or Brown's are in the 'True Crime' or 'History' sections of booksellers or libraries!!!!!

Muttley