Among its founders were Norwid Neugebauer, Marian Januszajtis-Żegota, Henryk Bagiński and Eugeniusz Homer.
Before its legalization, the PDS operated as an underground organization called Polish Military Alliance (Polski Zwiazek Wojskowy, PZW).
Its objective was to prepare the Polish nation for fight for independence, with emphasis on training of officer corps of the future army.
In October 1910, the PZW took the name Armia Polska (Polish Army), organizing paramilitary courses in Austrian Galicia, as well as in Congress Poland and Vienna.
By the outbreak of the First World War, its membership grew rapidly, to over 6,000 members, divided into 127 so-called rifle teams.