The Ersatz Zenta class was a class of three planned light cruisers of the Austro-Hungarian Navy designed in the mid-1910s as part of a naval expansion program passed during a period of rising tensions in Europe. Several designs were proposed, including options for a so-called "yacht cruiser" that was to have been used by Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne. The design that was ultimately selected called for ships that were capable of speeds of at least 30 knots (56 km/h; 35 mph), with an armament of fourteen 12-centimeter (4.7 in) guns and a thin armored belt that was 20 millimeters (0.79 in) thick.