<Tr> <Td_colspan="3"> Inca Empire </Td> </Tr> <Tr> <Td_colspan="3"> Tawantinsuyu (Quechua) </Td> </Tr> <Tr> <Td_colspan="3"> <Table> <Tr> <Td> </Td> <Td> 1438--1533 </Td> <Td> </Td> </Tr> </Table> </Td> </Tr> <Table> <Tr> <Td> </Td> <Td> 1438--1533 </Td> <Td> </Td> </Tr> </Table>

How did the inca keep their empire united