<Tr> <Td_colspan="2"> In office 3 September 1841--27 June 1846 </Td> </Tr> <Tr> <Th> Prime Minister </Th> <Td> Sir Robert Peel </Td> </Tr> <Tr> <Th> Preceded by </Th> <Td> The Viscount Melbourne </Td> </Tr> <Tr> <Th> Succeeded by </Th> <Td> The Marquess of Lansdowne </Td> </Tr>

Who was the iron duke that defeated the emperor napoleon