Sun Tzu proved on the battlefield that his theories were effective (for example, at the Battle of Boju), that he had a successful military career, and that he wrote "The Art of War" based on his tested expertise. However, the "Zuozhuan", a historical text written centuries earlier than the "Shiji", provides a much more detailed account of the Battle of Boju, but does not mention Sun Tzu at all. Beginning around the 12th century, some scholars began to doubt the historical existence of Sun Tzu, primarily on the grounds that he is not mentioned in the historical classic "Zuo zhuan", which mentions
Christianity in the 6th century that before a battle against one of the kings of the Alamanni, and had thus attributed his victory to Jesus. Such utilitarian thoughts were the basis of most conversions of rulers during this period. The Christianization of the Franks lay the foundation for the further Christianization of the Germanic peoples. Cosmas Indicopleustes, navigator and geographer of the 6th century, wrote about Christians, bishops, monks, and martyrs in Yemen and among the Himyarites. In the 5th century a merchant from Yemen was converted in Hira, in the northeast, and upon his return led many to Christ. It is unclear when Christianity