Eviction of the Ostrogoths from Rome, and the re-unification of all Italy under Roman rule. 561 to 592: Buddhist monk Jnanagupta translates 39 sutras from Sanskrit to Chinese. 563: The monastery on Iona is founded by St. Columba. 566: Birth of Lǐ Yuān, founder of the Tang dynasty and Emperor of China under the name of Gaozu (618-626) 568: Lombards invade Italy and establish a federation of dukedoms under a king. 569: Nubian kingdom of Alodia converts to Christianity. 569: Nubian kingdom of Makuria converts to Christianity. 570: Birth of the last Islamic Prophet Muhammad. 574: The Roman Empire is invaded by various Slavs, who plunder the Balkans. 577: China's Chen dynasty invents matches. 578: The world's oldest ongoing company, Kongō Gumi, is founded in Osaka, Japan. 579–590: Reign of Persian Shah Hormizd IV. 582–602: Reign of Roman Emperor Maurice. 585: Suebian Kingdom conquered by Visigoths in Spain. 587: Reccared, king of the Visigoths in Spain, converts to Catholicism. 588: Shivadeva ascends the throne of the Lichchhavi dynasty in Nepal. 589: Third Council of Toledo adds the "filioque" clause to the Nicene Creed in Spain. 589: China reunified under the Sui dynasty (589 – 618). 590: Gregory the Great succeeds Pope Pelagius II (who dies of plague) as the 64th pope. 594: Beginning of the Bengali Calendar or (বঙ্গাব্দ Bônggabdô or Banggabda). 595: Pope Gregory sends Roman monks led by Augustine to England. Inventions, discoveries, introductions Dionysius Exiguus creates the Anno Domini system, inspired by the birth of Jesus, in 525. This is the system upon which the Gregorian calendar and Common Era systems are based. The technology of cutting and polishing diamonds was invented in India, Ratnapariksha, a text dated to 6th century talks about diamond cutting. Backgammon (nard) invented in Persia by Burzoe. Chess, as chaturanga, entered Persia from India and was modified to shatranj. Breast-strap horse harness in use in Frankish kingdom. Byzantine Empire acquires silk technology from China. Chen dynasty from China invents matches in 577. Silk is a protected palace industry in the Byzantine Empire. Vaghbata, Indian medical books. In 589 AD, the Chinese scholar-official Yan Zhitui makes the first reference to the use of toilet paper in history. Significant to the history of agriculture, the Chinese author Jia Sixia wrote the treatise Qi Min Yao Shu in 535, and although it quotes 160 previous Chinese agronomy books, it is the oldest existent Chinese agriculture