It is true that Poland has a long history of warfare. If you are ready to do digging of your own, I can point you in some directions, based on what I remember form school and few university courses. Some of the more well known figures and battles form Polish military history:

• Boleslaw Chrobry ("chrobry" roughly means "brave"), ruling 992-1025, first crowned king of Poland, was famous for numerous wars against his neibourghs. He came as far east as Kiev, briefly took control of Czechy and Slovakia, and succesfuly defended against German emperor Henry II.

• In 1410, allied Polish and Lithuanian forces crushingly defeated powerful Teutonic Order in Battle of Grunwald, forever changing balance of power in the region. It is, without a doubt, best known Polish victory as far as Poles are concerned, historically often used in propaganda, nowadays reenacted every year.

• Jan III Sobieski, ruling 1674 - 1696, was known as a great warrior before he was crowned - in fact, his military skill was one of the reasons he won the election. His by far most famous accomplishment is Battle of Vienna in 1683, where he aided Habsburgs in breaking Turkish siege of the city. Supposedly, it was biggest cavalry charge in history of warfare.

• Speaking of cavalry, you might be intrested in hussary - polish elite heavy cavalry. They had some very impressive victories, like in Battle of Klushino, where they soundly defeated enemy despite being outnumbered 1 to 4. That is recurring theme, as army of Polish-Lithuanian Commonwealth never was particulary big, even when we could in theory afford it. Hetman Stanislaw Zolkiewski, commander under Klushino, is by the way one of the most renowed polish generals.

I'm sorry for not giving you more insightful info, or providing you with good sources. Few history books I have at hand are in Polish anyway. But since there is not much going on in this topic right now, I figured I would hop in and tell you about some basic stuff.

As someone who works on the region and someone of Polish heritage, I would point away from the military accomplishments and try to examine some of the cultural legacies. At the height of confessional conflicts in the sixteenth century, Poland-Lithuania was arguably the most religiously diverse and certainly most tolerant state in Europe. In addition to its marginal Roman Catholic majority, it also included subjects who were Orthodox, Armenian Apostolic (from among the traditional churches), but also Lutheran, Calvinist, Anti-Trinitarian and Anabaptist communities. The Anabaptists, in particular, were ruthlessly hunted down by both Catholics and Protestants elsewhere in Europe. In Poland-Lithuania, many found not only safety, but legal protection via royal decree. The Polish-Lithuanian state was also home to diverse Jewish communities. These included a small group of Karaite Jews, who, due to their rejection of the Talmud, were viewed as heretics by most mainstream Jews. Lastly, it also included an Islamic Tatar populace that were not only tolerated, but served with distinction in the military campaigns of the Commonwealth. In this period, Polish subjects spoke a variety of languages, including Polish, Ruthenian, German, Yiddish, Lithuanian, Latin, Armenian and Tatar. This diversity often stood in stark contrast to most sixteenth century European states, where confessional strife was not only an ever present threat, but royal policy ruthlessly promoted confessional uniformity.

The crowning moment of this period of confessional tolerance was the 1573 Confederation of Warsaw, drawn up by the religiously diverse nobility. It enshrined religious freedom in public and private for all free subjects, regardless of whether they were nobles, townfolk or otherwise. Prior to actual crowning, anyone elected to the Polish crown had to swear an oath to uphold these ideals.

Scholars have referred to Poland-Lithuania as "the state without stakes" and "a state without (religious) conflagration." Poland-Lithuania never witnessed an inquisition, never saw an auto-da-fe, never had its own Oliver Cromwell.

I highly recommend a recent piece of scholarship on the Polish-Lithuanian conviviencia in Early Modern Vilnius: David Frick, Kith, Kin, and Neighbors: Communities and Confessions in Seventeenth-Century Wilno (Ithaca, NY: Cornell University Press, 2013); Also worthwhile and accessible content-wise: Janusz Tazbir, A State without Stakes: Polish Religious Toleration in the Sixteenth and Seventeenth Centuries (New York: The Kościuszko Foundation, 1973); Norman Davies, God's Playground: A History of Poland, Vol. 1: The Origins to 1795, New York: Columbia University Press, 2005.