Giovanni Antonio Canaletto, London Bridge, a drawing

The great Venetian painter Canaletto came to London in 1746, seeking British patrons who had cut short their Grand Tours when the War of Austrian Succession reached Italy. Apart from a visit to Venice of a few months in 1750-51, Canaletto remained in the country until 1755. His drawings combine elegance with workaday description in a way that is especially evocative of London of the period.The first London Bridge was built by the Romans. Several bridges were built and destroyed in the early middle ages, but the one built between 1176 and 1209 stood until the 1820s. It was constructed on nineteen narrow arches with a drawbridge in the centre that was lifted occasionally to allow tall ships to pass through, and houses lined its sides like any City street. The piers and their foundations took up eighty per cent of the river bed and the bridge acted like a dam to hold water back.The view has a Venetian feel, with graceful boats floating on the tranquil water, workers about their business on the south bank, teetering houses on the bridge itself and, on the north bank, grand buildings and towers - Fishmongers' Hall, the Monument, the Water Tower and the church of St Magnus Martyr. Between 1758 and 1762 the bridge was overhauled by George Dance and Robert Taylor: the houses were removed, the roadway widened and several of the spans enlarged to allow greater access for shipping.