In 1853, a single-track line became operational from Verona to Porto Mantovano (Mantua). In the same year, the Austrian Empire began construction of the Brenner Railway over the Brenner Pass at 1,371 m, connecting County of Tyrol and Kingdom of Lombardy-Venetia. The Brenner Railway was among Austria's first trans-alpine heavy railways along with the now defunct Franzensfeste-Marburg Railway (Fortezza in Italy and Maribor in Slovenia).