Kiautschou Bay concession
Between 1891 and 1897, the two ships were heavily rebuilt as armored cruisers. They were significantly rearmed with a large number of medium and smaller caliber guns. "Kaiser" served in Asian waters from 1897 to 1899, while her sister was on the Asia station from 1898 to 1900. Admiral Otto von Diederichs, then the commander of the East Asia Squadron, used "Kaiser" for his flagship. The ship was involved in the Kiautschou Bay concession seizure in November 1897 and was later deployed to protect German interests in the Philippines during the Spanish–American War in 1898.