Europe is a continent. Many European countries, real and fictional, have featured in The Simpsons. The largest country is Russia and the smallest country in Europe is Vatican City.
In The Trouble with Trillions, it was revealed that Europe never fully reconstructed after WWII. Homer, who has been audited by the IRS, is shown a clip from 1945, in which President Harry S. Truman printed a trillion dollar bill to send to Europe. Truman had sent war veteran Charles Montgomery Burns to deliver the money to Europe. However, seeing as he was already one of the richest citizens of the United States, Burns stole the bill and kept it for himself, therefore secretly becoming the wealthiest man in the world. Subsequently, Europe only partially reconstructed, and was left in ruins. This would cause future Europeans to be snobbish to Americans.