Blücher, the last armored cruiser built by the Imperial German Navy, was launched.

SMS Blücher was the last armored cruiser built for the German Kaiserliche Marine in the late 1900s. She was designed in response to the latest British armored cruisers, but the British had already begun work on the Invincible-class battlecruisers, which marked a significant increase in firepower over earlier armored cruisers. Blücher was armed with a main battery of twelve 21 cm (8.3 in) guns, compared to the eight 30.5 cm (12 in) guns of the British ships. Blücher entered service after the Invincibles were commissioned, and as a result, was obsolescent at the start of her career.

The armored cruiser was a type of warship of the late 19th and early 20th centuries. It was designed like other types of cruisers to operate as a long-range, independent warship, capable of defeating any ship apart from a pre-dreadnought battleship and fast enough to outrun any battleship it encountered.

The Imperial German Navy or the Kaiserliche Marine was the navy of the German Empire, which existed between 1871 and 1919. It grew out of the small Prussian Navy, which was mainly for coast defence. Kaiser Wilhelm II greatly expanded the navy. The key leader was Admiral Alfred von Tirpitz, who greatly expanded the size and quality of the navy, while adopting the sea power theories of American strategist Alfred Thayer Mahan. The result was a naval arms race with Britain, as the German navy grew to become one of the greatest maritime forces in the world, second only to the Royal Navy.