What did the Polish soldiers do during the 1939 invasion?

During the 1939 invasion of Poland, Polish soldiers fought valiantly against the German Wehrmacht and the Soviet Red Army, which invaded from the east shortly after Germany's assault. Despite being outnumbered and outgunned, they engaged in numerous defensive battles, notably at Westerplatte and the Battle of Bzura. Ultimately, the overwhelming might of the German blitzkrieg tactics led to the rapid defeat and occupation of Poland by the end of September 1939. Many soldiers retreated to continue fighting alongside Allied forces or to join resistance movements.