The Southern Railway is a railroad in Austria that runs from Vienna to Graz and the border with Slovenia at Spielfeld via Semmering and Bruck an der Mur. It was originally built by the Austrian Southern Railway company and ran to Ljubljana and Trieste, the main seaport of the Austro-Hungarian Monarchy. The two-track, electrified section that runs through the current territory of Austria is owned and operated by Austrian Federal Railways (ÖBB) and is one of the major lines of the country.