K'ak' conquers Waka on (January 8), Tikal (January 16) and Uaxactun. 381: First Council of Constantinople reaffirms the Christian doctrine of the Trinity by adding to the creed of Nicaea. 383: Battle of Fei River in China. 395: The Battle of Canhe Slope occurs. 395: Roman emperor Theodosius I dies, causing the Roman Empire to split permanently. Late 4th century: Cubiculum of Leonis, Catacomb of Commodilla, near Rome, is made. Late 4th century: Atrium added in the Old St. Peter's Basilica, Rome. Inventions, discoveries, introductions The Stirrup was invented in China, no later than 322. Kama Sutra, dated between c. 400 BC to c. 300 AD. Iron pillar of Delhi, India is the world's first Iron Pillar. Trigonometric functions: The trigonometric functions sine and versine originated in Indian astronomy. Codex Sinaiticus and the Codex Vaticanus Graecus 1209, are the earliest Christian bibles. Book of Steps, Syriac religious discourses. References 1st millennium 04th century