Flint was the first great castle built for Edward I during his campaigns to defeat Llywelyn ap Gruffudd and subdue the Welsh. The castle was built on land next to the Dee estuary between 1277 and 1284. The inner ward is a square with a large tower at each corner. The southeast tower was larger than the others and separated by its own moat and drawbridge. The Dee estuary fed water into a moat that surrounded the landward side of the castle.

It was at Flint Castle in August 1399 that King Richard II was captured by Henry of Bolingbroke and forced to return to London and abdicate in favour of Henry who became King Henry IV, while Richard was eventually taken to Pontefract Castle in Yorkshire where he died in custody.

At the end of the Civil War the castle was demolished leaving only a few remnants that can be seen today.