The two "Roon"-class cruisers were ordered in 1902 as part of the fleet expansion program specified by the Second Naval Law of 1900. The two ships were incremental developments of the preceding s, the most significant difference being a longer hull; the additional space was used to add a pair of boilers, which increased horsepower by and speed by . The launch of the British battlecruiser in 1907 quickly rendered all of the armored cruisers that had been built by the world's navies obsolescent.