The BL 12-inch Gun was a British naval artillery piece developed in the late 19th century. It was primarily used on battleships and coastal defense installations, designed to fire heavy shells at long ranges. The gun had a caliber of 12 inches (305 mm) and was known for its powerful performance in naval engagements. This artillery piece was part of the British Royal Navy's efforts to modernize its fleet during the Victorian era. The BL 12-inch Gun played a significant role in naval warfare, contributing to the effectiveness of battleships like the HMS Dreadnought and influencing naval tactics in the early 20th century.