Christmas in Poland is a major annual celebration, as in most countries of the Christian world. The observance of Christmas developed gradually over the centuries, beginning in ancient times; combining old Polish pagan customs with the religious ones introduced after the Christianization of Poland by the Catholic Church. Later influences include the mutual permeating of local traditions and various folk cultures. It is one of the most important religious holidays for Poles, who follow a somewhat strict traditional custom. Christmas trees are decorated and lit in family rooms on the day of Christmas Eve. Other trees are placed in most public areas and outside churches. Christmas in Poland is called "Boże Narodzenie", which translates to 'God's Birth'.