The Viking conversion to Christianity was a gradual process, beginning around the 9th century and continuing through the 11th century. Contact with Christian Europe through trade, raids, and settlements introduced Viking leaders and communities to the religion. Missionaries, including Saint Ansgar, worked to spread Christianity, and several Viking rulers, such as King Olaf Tryggvason of Norway, promoted Christian practices. Conversion often provided political and economic advantages, as Christian kings formed alliances with European powers. By the 11th century, most of Scandinavia had adopted Christianity, blending it with Norse customs. Churches replaced pagan temples, and Christian burials became common, marking a major cultural shift.