Why did Britain launch HMS Dreadnought in 1906?

Britain launched HMS Dreadnought in 1906 primarily to capitalize on advancements in naval gunnery and design that rendered existing battleships obsolete.12

By 1904, analysis of naval engagements in the Spanish-American War and the Russo-Japanese War demonstrated that large-caliber guns were significantly more effective at long ranges than the traditional "mixed-battery" approach. Furthermore, firing multiple calibers created confusing water splashes, which made range-finding and aiming difficult.2

To address these issues, the British pioneered a "single-calibre" armament design, mounting 10 12-inch guns. Additionally, Dreadnought was the first battleship to utilize steam turbines, allowing it to reach a speed of 21 knots—a significant improvement over the 18-knot limit of contemporary vessels. By integrating these innovations, Britain sought to maintain naval superiority, effectively triggering a new era of naval ship development that other world powers quickly followed.12