This classic "Veduta" - or Venetian view - has been attributed to both Marieschi and Guardi. Could it be by either of these two masters of 18th century Venetian vistas or another hand altogether? Francesco Guardi was born into a family of Venetian painters in 1706 and is known as the last of the classic Venetian school, influenced by the hugely popular Canaletto. His paintings are incredibly atmospheric, full of light, dotted, spirited brushstrokes, giving an almost impressionistic feel. Guardi's paintings go for an incredible amount of money - one of his paintings recently sold for £26million. Michele Marieschi died in 1743 at the age of 34 but was incredibly productive in his short career. He trained as a theatrical scene painter and for him perspective is crucial. Marieschi made Venice look grander and more dramatic than the reality. His paintings were hugely popular with visiting British tourists, keen to take home a memento of their trip to the magical city. Although less valuable than Gaurdi, Marieschi's paintings can still sell in the hundreds of thousands.