Raiding at the Full Moon

The Göktürks timed their raids by the moon.^[1] The Sui Shu states this in a single sentence of its account of their customs. They waited until the moon was about to be full, and then they went out raiding: 候月將滿，輒為寇抄.^[1] In the text, the sentence follows the remark that they had no script and cut notches in wood for their agreements. It comes before the list of their punishments.^[1]

The witnesses

The Bei Shi and the Tongdian repeat the sentence.^[2] The Bei Shi copies it from the Sui Shu and inserts it into the Zhou Shu’s account of Göktürk custom.^[3] The three texts are therefore one witness. The older Zhou Shu does not have the sentence.^[4]

The moon and war

The Shiji reports the same custom for the Xiongnu. Before an undertaking they watched the stars and the moon. They attacked when the moon was full and withdrew when it waned.^[5] The Sui Shu itself ends its account of Göktürk custom with the remark that these customs were broadly those of the Xiongnu.^[1] The likeness is the Sui Shu’s own comparison. It makes no statement about descent. One account counts the watching of the moon before a campaign as attested from the Xiongnu on, and sees the Göktürks’ waiting for the full moon as the same practice.^[6]

Some scholars hold that the Göktürks kept the same custom as the Mongols of Chinggis Khan. The Mongols began a campaign or any other weighty undertaking only at the half moon or the full moon.^[7] The sources of the khaganates name no god of the moon. They record only that the moon was watched before war. The Moon Father of later Turkic belief is Ay Ata.

The evidence is a single sentence. It describes a practice of war, not a belief.