England is home to many famous castles that are an important part of the country's history. Warwick Castle, located in Warwick, was first built by William the Conqueror in 1068. Did you know that the castle was built on a hill to make it safer from attacks? The attackers would get tired before reaching the castle. Bamburgh Castle, located on the coast of Northumberland, has been standing for over 1,400 years and was once captured by the Vikings in 993. Stirling Castle, which dates back to the 12th century, was built on a volcanic hill called Castle Hill and protected the lowest crossing point of the River Forth for centuries. Dundrum Castle, believed to have been built around 1177, is now a ruin and features a Motte and Bailey style castle. Pembroke Castle, built in the 11th century, is the birthplace of Henry Tudor, the founder of the Tudor dynasty. Raglan Castle, located in Monmouthshire, is associated with William ap Thomas, who fought in the Battle of Agincourt. Dunluce Castle, located in Northern Ireland, was first built by the MacQuillan family in the 1500s but was later captured by the famous warrior chief Sorely Boy MacDonnell. Urquhart Castle, located on the shores of Loch Ness, was once one of the largest castles in Scotland and has seen many battles over the centuries. Royal Mail has introduced a new stamp collection featuring these ancient castles from across England. The stamps include a miniature sheet featuring castles from the Norman period and the four royal palaces. 'Castles are one of the most recognizable features of the English landscape, and this stamp series celebrates the skill, ambition, and endurance of these extraordinary structures, as well as the four royal palaces,' said David Gold, Director of External Affairs at Royal Mail. The artwork was created by English illustrator Rob Ball, and the stamps will be available for purchase starting May 21st.