Which period in medieval western Europe is known as 'Dark Ages'?

The Early Middle Ages have often been called the Dark Ages, and to some extent  they were truly dark. The people led a miserable life. Education was very uncommon. The helplessness of the comman man the arbitary rule of the king and the barons and the absence of national unity-all these conditions were common in Europe. The term 'Middle Ages' does not cover a uniform period for all the countries of the world.For Europe and the Westren World , the 'Middle Ages' are generally considered to be the period between AD 500 and AD 1500.