Slovakia
Slovakia had an army at only six months old, but when Germany asked the Slovaks to help attack Poland, they agreed. They sent an army group, called Field Army Bernolák under the command of Slovak General Ferdinand Catlos. Their campaign began on September first, 1939. They occupied the Polish town of Tatranska Javorina and several other Polish areas (which are still part of Slovakia today.) They only faced one Polish force, the Karpaty Army. At the end of their attack, they had occupied much of Southern Poland with the cost of only 37 men killed and 114 men wounded.
- Also see Slovak invasion of Poland
Read more about this topic: Opposing Forces In The Polish September Campaign