The modern-day Brenner line was built in several different stages: the southern section between Bolzano and Verona was inaugurated on May 16th 1859. When the Austro-Hungarian Empire lost Veneto to Italy in 1866, Ala became the border station and the section from Ala to Verona was taken over by Italy.
Connecting Bolzano and Innsbruck (already covered by the Austro-Hungarian railway network), the Brenner section was inaugurated on 24th August 1867 . It was then that the area once known as Tyrol could boast its first transalpine railway connection in the Austo-Hungarian Empire: a line connecting Italy and Germany. As an integration to the Brenner section, Austria commissioned the Maribor – Fortezza line, which was built by Südbahngesellschaft, a company in very good relations with the imperial family.
Soon this new line showed that its capacity was not high enough and the Brenner line became a bottleneck. There was still only a single pair of tracks form Ala the the Brenner Pass, while the railway infrastructure in North Tyrol had been boosted in the meantime and Innsbruck had become an important junction. South Tyrol and Trentino were lagging behind.
It took some time to electrify this line. Electrification work was complete in 1928 between Innsbruck and Brennersee, not far from the Italian border, using the Austrian system of 15 kV, 16 2/3 Hz single-phase AC. At the same time, electrification in South Tyrol was carried out by installing the Italian system, 3.6 kV, 16 2/3 three-phase AC. There remained a short gap between Brenner and Brennersee, however, and it was not until 1934 that the two systems were joined in Brenner border station. In 1965 the Italian three-phase system was replaced with the new standard of 3 kV DC.
Thus, there are still two different systems bordering at Brenner today, the Italian system using 3000 Volt direct current, and the Austrian/German system using 15 kV/16 2/3 Hz Volt alternating current). As a result, international trains are still forced to stop and change engines when crossing the border. The new FLIRT trains, purchased in 2008 by the Provincial Government of Bolzano, are capable of running on both networks.