 The Tegetthoff class ( sometimes erroneously named the Viribus Unitis class ) was the sole class of dreadnought battleship built for the Austro @-@ Hungarian Navy . Four ships were built , Viribus Unitis , Tegetthoff , Prinz Eugen and Szent István . Three of the four were laid down in Trieste , with Szent István being built at Rijeka , to incorporate both parts of the dual monarchy into the construction of the ships . The smaller size of the shipyards in Rijeka meant that Szent István was built three years after her sisters , with slightly different characteristics . 
