The Ostrogoths were the eastern branch of the later Goths. The other major branch was the Visigoths. The Ostrogoths started with the Greutungi – a branch of the Goths who moved southward from the Baltic Sea during the 3rd and 4th centuries. They built an empire stretching from the Black Sea to the Baltic. They traded with the Roman Empire. The empire was largest under King Ermanaric.