<Li> Leader of the House of Lords </Li> <Tr> <Th_colspan="3"> 241 days </Th> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> The Right Honourable Edward Smith - Stanley 14th Earl of Derby KG PC (1799--1869) </Td> <Td> 28 June 1866 </Td> <Td> 25 February 1868 </Td> <Td>--</Td> <Th> <Ul> <Li> First Lord of the Treasury </Li> <Li> Leader of the House of Lords </Li> </Ul> </Th> <Td> Conservative </Td> <Td> Derby--Disraeli III </Td> <Td> </Td> </Tr> <Ul> <Li> First Lord of the Treasury </Li> <Li> Leader of the House of Lords </Li> </Ul>

When was the first prime minister of england elected