Complex sentence: Mentioned in several sources up to the third century A.D. when they apparently split into at least two groups, the Greuthungi in the east and Tervingi in the west, the two Gothic tribes shared many aspects, especially recognizing a patron deity which the Romans named Mars.
Split into simpler sentences: Mentioned in several sources up to the third century A.D. when they apparently split into at least two groups, the Greuthungi in the east and Tervingi in the west. The two tribes shared many aspects, especially recognizing a patron deity which the Romans named Mars.