The Prinz Adalbert class was a group of two armored cruisers built for the German Kaiserliche Marine (Imperial Navy) under the terms of the Second Naval Law. Two ships of the class were built, Prinz Adalbert and Friedrich Carl, between 1900 and 1904. The two ships were heavily based on the previous armored cruiser, Prinz Heinrich, with a series of incremental improvements. Their armor layout was revised slightly to improve internal protection and their main battery consisted of four 21 cm (8.3 in) guns instead of the two 24 cm (9.4 in) carried by Prinz Heinrich. The new ships also received more powerful propulsion systems, making them slightly faster. Prinz Adalbert spent her peacetime career as a gunnery training ship while Friedrich Carl initially served as the flagship of the fleet's re