Best source for cannon info is the OP Lore Summaries.

For Poland...

[quote]
Declared its independence in 1922 amidst the Great War. Later, it opens up ports and becomes a significant trading power. Poland took advantage of uprisings in Czech Republic in 1970, and the Austrian territory was quickly absorbed. Austria, unable to quell the uprising and confront Poland, lost the territory without resistance. Poland became the Slavic Union shortly after. In 1975, Poland intervened in a Hungarian invasion of Ukraine, managing to repel the Hungarian forces. Ukraine joined the Slavic Union in exchange for protection after the war.

In 1976, Poland deployed forces into Moscow to quell the violence there. They also provided arms to Armenia during their rebellion against the Ottoman Empire.[/quote]