How many series has Robert Muchamore written?

Robert Muchamore has written five series:

- CHERUB (12 books, 2004–2014)

- Henderson's Boys (5 books, 2009–2013)

- Rock War (4 books, 2012–2015)

- Secret (5 books, 2015–2019)

- Robin Hood (2 books, 2020–2021)