The Red Force is a fictional para-military organization in the The Flag Republic of Red & Blue series, that co-rules the fictional Cross Castle, disputed with the Blue Force. Originally a castle monarchy, which was split with the Blue monarchy, due to ideology, Red being closer to hereditary monarchy, and Blue to elective. This led it to form a feud to multiple generations. In the early 19th century, Pier XV, abolished the monarchy in an agreement with the Blues. The Red Force was formed not long from the Flag War, and a sudden raid was attempted, later led to a provocation between the forces, and a fight begun in the castle to capture the flags.