The origins of the Christmas tree can be traced back to ancient times. In many cultures, evergreen trees and other plants were used to represent the rebirth of life and the return of the sun. In ancient Rome, they were used in a festival honoring the god of agriculture, and in northern Europe, they were associated with the Norse god, Odin. The tradition of bringing evergreen trees into the home during the winter months was adopted by German Christians in the 16th century.