<Tr> <Td> 14 </Td> <Td> 16 18 </Td> <Td> William Pitt the Younger </Td> <Td> Tory </Td> <Td> 1783--1801 1804--1806 </Td> <Td> 04 </Td> <Td> 12 </Td> <Td> 05 </Td> <Td> 03 </Td> </Tr> <Tr> <Td> 15 </Td> <Td> 17 </Td> <Td> Henry Addington </Td> <Td> Tory </Td> <Td> 1801--1804 </Td> <Td> 39 </Td> <Td> 36 </Td> <Td> 39 </Td> <Td> 36 </Td> </Tr> <Tr> <Td> 16 </Td> <Td> 19 </Td> <Td> Baron Grenville </Td> <Td> Whig </Td> <Td> 1806--1807 </Td> <Td> 43 </Td> <Td> 39 </Td> <Td> 40 </Td> <Td> 35 </Td> </Tr> <Tr> <Td> 17 </Td> <Td> 21 </Td> <Td> Spencer Perceval </Td> <Td> Tory </Td> <Td> 1809--1812 </Td> <Td> 36 </Td> <Td> 38 </Td> <Td> 47 </Td> <Td> 33 </Td> </Tr>

Who is regarded as one of the greatest prime ministers