膠州湾租借地
Both ships served in the East Asia station with the East Asia Squadron; "Prinzess Wilhelm" played a major role in the seizure of the Kiautschou Bay concession in November 1897, under command of Admiral Otto von Diederichs. The two ships were sent to safeguard German interests in the Philippines after the Battle of Manila Bay during the Spanish–American War. There, "Irene"s presence caused tensions with the American squadron occupying the islands. Both ships returned to Germany at the turn of the century, and remained in European waters until 1914, when they were removed from active service. They were reduced to secondary roles—"Irene" was used as a submarine tender and "Prinzess Wilhelm" was hulked—and continued to serve until the early 1920s, when they were sold for scrap.