The BL 15-inch Gun was a British naval artillery piece developed in the early 20th century. It was primarily used during World War I and World War II, mounted on various battleships and coastal defense installations. The gun was known for its powerful performance and long-range capabilities, making it a significant asset in naval warfare. This artillery piece fired a 15-inch (381 mm) shell, which could penetrate heavy armor and deliver devastating damage to enemy ships. The BL 15-inch Gun played a crucial role in several naval engagements, showcasing the advancements in military technology during its time.