The First Naval Law in Germany, passed in 1898, envisioned a force of twelve armored cruisers intended for overseas service in the German colonies.
However, the German Navy required cruisers for operations with the fleet as well, and attempted to design ships that could fulfill both roles, primarily due to budget constraints.
The first product of the 1898 Naval Law, Prinz Heinrich, was an alteration of an earlier vessel, Fürst Bismarck, equipped with fewer guns and thinner but more comprehensive armor in a trade-off for higher speed and lower cost.
According to the law, one large cruiser was to be built per year, so work began immediately on a follow-on vessel to fulfill the requirement.

The subsequent design—that of the Prinz Adalbert class—was prepared in 1899–1900, and was an improvement on Prinz Heinrich.
The basic hull size and shape remained largely identical, but modifications were made to the armament and armor layout.
Four quick-firing 21 cm (8.3 in) guns in twin turrets were substituted for the pair of slower 24 cm (9.4 in) guns mounted singly on the older vessel, as the design staff had by that time begun to question the wisdom of limiting the heavy gun battery to just two guns.
The 21 cm caliber would remain the standard for all subsequent armored cruiser designs.
The ships' secondary battery was kept largely the same as that of Prinz Heinrich, apart from the addition of another pair of 8.8 cm (3.5 in) guns.

Armor thickness remained similar in strength to that of Prinz Heinrich, though it was made more comprehensive, the primary improvement being to the upper belt, which was connected to the main battery barbettes by oblique armored bulkheads.
The deck thickness was also increased, and a new propulsion system that was about 10 percent more powerful than Prinz Heinrich's increased the ships' top speed by .5 knots (0.93 km/h; 0.58 mph) compared to the earlier vessel.
The First Naval Law in Germany, passed in 1898, envisioned a force of twelve armored cruisers intended for overseas service in the German colonies. However, the German Navy required cruisers for operations with the fleet as well, and attempted to design ships that could fulfill both roles, primarily due to budget constraints. The first product of the 1898 Naval Law, Prinz Heinrich, was an alteration of an earlier vessel, Fürst Bismarck, equipped with fewer guns and thinner but more comprehensive armor in a trade-off for higher speed and lower cost. According to the law, one large cruiser was to be built per year, so work began immediately on a follow-on vessel to fulfill the requirement. 
The subsequent design—that of the Prinz Adalbert class—was prepared in 1899–1900, and was an improvement on Prinz Heinrich. The basic hull size and shape remained largely identical, but modifications were made to the armament and armor layout. Four quick-firing 21 cm (8.3 in) guns in twin turrets were substituted for the pair of slower 24 cm (9.4 in) guns mounted singly on the older vessel, as the design staff had by that time begun to question the wisdom of limiting the heavy gun battery to just two guns. The 21 cm caliber would remain the standard for all subsequent armored cruiser designs. The ships' secondary battery was kept largely the same as that of Prinz Heinrich, apart from the addition of another pair of 8.8 cm (3.5 in) guns.
Armor thickness remained similar in strength to that of Prinz Heinrich, though it was made more comprehensive, the primary improvement being to the upper belt, which was connected to the main battery barbettes by oblique armored bulkheads. The deck thickness was also increased, and a new propulsion system that was about 10 percent more powerful than Prinz Heinrich's increased the ships' top speed by .5 knots (0.93 km/h; 0.58 mph) compared to the earlier vessel.
Prinz Adalbert-class cruiser