The Urartians became a powerful force beginning around 1000 B.C. in the mountains of Eastern Anatolia. Their origins have been traced to the Hurians who entered the region from the Caspian Sea. As the Hittite influence started to decline in Anatolia, that of the Urartians grew. They established themselves in what was known as Armenia, and their capital was built at the city of Van. This is the great fortress known as Toprakkale. The Urartian Kingdom expanded by unifying nomadic tribes in a system of defense against outside intruders. The height of their power was seen during the 8th and 9th centuries B.C., when they controlled Northern Syria and Mesopotamia as well as the region in Anatolia, They were a warlike nation with a distinct talent for breeding horses for use in battle. Their language was unlike that of the Hittites for it was not Indo-European in origin; though it was not Semitic, it was written in a cuneiform script that is related to the Assyrian writing. At their capital in Van, the ancient Tuspa, magnificent temples were built to the god Haldi, and animals were sacrificed in his honor.