Alois Franz Trenker was born on 4 October 1892 in Urtijëi, Tyrol (German: St. Ulrich in Gröden, Italian: Ortisei) in the Austro-Hungarian Empire (in present-day northern Italy).

[1] His father Jacob Trenker was a painter from North Tyrol, and his mother Karolina (née Demetz) was from Urtijëi in Val Gardena.

At the start of World War I, Trenker fought as a cadet in an Austro-Hungarian heavy artillery unit on the Eastern Front in Galicia and Russisch-Polen.

He would write 23 books based on his war experiences, the most important of which were Fort Rocca Alta and Berge in Flammen, the latter of which was made into the 1931 film Mountains on Fire.

Trenker stated that the film's plotline of a Tyrolean mountaineer Severin Anderlan leading a revolt against occupying French forces in 1809, during the Napoleonic Wars.

The greatest Tirolean patriot Andreas Hofer was a proto-type of "Severin Anderlan" ... Trenker was designed to mirror what was happening in contemporary Germany as it rejected the terms of the Treaty of Versailles.

[2] The main theme of Trenker's work was the idealization of peoples connection with their homeland and pointing out the decadence of city life (most clearly visible in his 1934 film Der verlorene Sohn (The Prodigal Son).

His impersonation of a hungry, downtrodden immigrant in depression era New York was regarded as one of the seminal scenes for future Italian neorealism by the likes of Roberto Rossellini.