<Tr> <Th> Astrid Peth </Th> <Td> Kylie Minogue </Td> <Td> 2007 Special </Td> <Td_colspan="2"> "Voyage of the Damned" </Td> </Tr> <Tr> <Th> Sarah Jane Smith </Th> <Td> Elisabeth Sladen </Td> <Td> </Td> <Td> "The Stolen Earth" </Td> <Td> "Journey's End" </Td> </Tr> <Tr> <Th> Jackson Lake </Th> <Td> David Morrissey </Td> <Td> 2008--2010 Specials </Td> <Td_colspan="2"> "The Next Doctor" </Td> </Tr> <Tr> <Th> Lady Christina de Souza </Th> <Td> Michelle Ryan </Td> <Td> 2008--2010 Specials </Td> <Td_colspan="2"> "Planet of the Dead" </Td> </Tr>

Who was the longest serving doctor who companion