Si Deus Nobiscum quis contra nos (If God is with us, then who is against us)

The Polish–Lithuanian Commonwealth was formed by the 1569 Union of Lublin between the Kingdom of Poland and the Grand Duchy of Lithuania, and lasted until 1795. The new commonwealth was the largest and one of the most populous countries of 16th- and 17th-century Europe.

The new union possessed features unique among contemporary states: the Commonwealth's political system (known alternately as the Noble's Democracy or Golden Freedom) was characterized by strict checks upon monarchical power. These checks were enacted by a legislature (Sejm) controlled by the nobility (szlachta). This idiosyncratic system was a precursor to modern concepts of democracy, constitutional monarchy and federation. The two component states of the Commonwealth were formally equal, yet Poland was the dominant partner in the union.

The Polish–Lithuanian Commonwealth was marked by high levels of ethnic diversity and by unusual religious tolerance, though the degree of religious tolerance varied over time.

After several decades of power and greatness, the Commonwealth entered a period of protracted political, military and economic decline. Its growing weakness led to its partitioning among its more powerful neighbors, Austria, Prussia and Russia, during the late 18th century.

Polish Lithuanian Anthem