Theodosius I (Greek: Θεοδόσιος Theodósios; 11 January 347 – 17 January 395), also called Theodosius the Great, was Roman emperor from 379 to 395. During his reign, he faced and overcame a war against the Goths and two civil wars. He was key in establishing the creed of Nicaea as the universal orthodoxy for Christianity. Theodosius was the last Emperor to have ruled over the entirety of the Roman Empire before its administration was permanently split between two separate, western and eastern courts.