<Table> Captain Underpants <Tr> <Td_colspan="2"> Cover of the first Captain Underpants book </Td> </Tr> <Tr> <Th> Author </Th> <Td> Dav Pilkey </Td> </Tr> <Tr> <Th> Illustrator </Th> <Td> Dav Pilkey </Td> </Tr> <Tr> <Th> Country </Th> <Td> United States </Td> </Tr> <Tr> <Th> Language </Th> <Td> English </Td> </Tr> <Tr> <Th> Genre </Th> <Td> <Ul> <Li> Children's novel </Li> <Li> Comedy </Li> <Li> Superhero fiction </Li> </Ul> </Td> </Tr> <Tr> <Th> Publisher </Th> <Td> Blue Sky (US), Scholastic (US) </Td> </Tr> <Tr> <Th> Published </Th> <Td> <P> September 1, 1997 - August 25, 2015 (main series) </P> (spin - offs from 2002 - present) </Td> </Tr> <Tr> <Th> Media type </Th> <Td> Print (hardcover and paperback) </Td> </Tr> </Table> <Tr> <Td_colspan="2"> Cover of the first Captain Underpants book </Td> </Tr>

When was the first captain underpants book written