The mid-19th century saw several short wars involving European countries, some of which overlapped. For example, the Austro-Prussian War (also known as the Seven Weeks' War, the German Civil War, the Brothers War or the Fraternal War) was fought between the Austrian Empire and the Kingdom of Prussia from 14 June to 22 July 1866; Prussia had allied with the Kingdom of Italy, linking this conflict to the Third Independence War of Italian unification between the Kingdom of Italy and the Austrian Empire, which lasted from 20 June to 12 August 1866. Liechtenstein, Austria’s diminutive Alpine neighbour, was involved in both.

The Principality of Liechtenstein had become an independent state and had declared permanent neutrality while, at the same time, maintaining close political ties with Austria. The Minister-President of Prussia, Otto von Bismarck, accused Liechtenstein of political manipulation within the wider German Confederation. As a consequence of this perceived bullying, tiny Liechtenstein sent 80 men out on the Austrian side, but did not engage in any actual fighting (they guarded the Brenner Pass).

The 80 Liechtensteiners fought no battles and suffered no casualties. On their way home in August 1866 their ranks were swelled by one: an Austrian liaison officer decided to join their contingent. As a result, 81 returned to Liechtenstein.

More Info: en.wikipedia.org