I first ran into this author browsing the stacks at Powells in Portland a couple of years ago. I bought "A Sailor of Austria" and loved it. Otto is a sort of central European Flashman who joins the Imperial Austrian Navy in the years leading up to WWI. Like Flashy, the stories are written in the form of memoir, looking back from an advanced old age. Unlike Flashy, Otto is not a coward and a cad, which makes him none the less likeable.
I soon bought most of the rest of the books: "The Two-Headed Eagle" and "The Emperor's Colored Coat." They were all well written, with a wealth of historical detail. Humor was present like a big heap of whipped cream on a slab of Sacher torte; the books were all very funny.
The final volume I bought, "Tomorrow the World", was a reprinted edition which came out last year. The original hardbacks were going for over $1,000. The Prohaska novels should be on your bookshelf next to the Flashman and Bartholomew Bandy series.
To read these, put a long CD of Strauss waltzes on autoreplay with low volume, and drink some Austrian or Czech beer. Prost!