What is "sinnion"

Sinnion (Σιννίων, Σισίννιος ; undetermined origin, perhaps Persian) was ruler of the Kutrigurs in the 6th century. Somewhere after 551, when the Utigurs led by Sandilch attacked the Kutrigurs who suffered great losses, the Kutrigurs made a peace treaty with Byzantine Empire, and 2000 Kutrigurs on gallop with wives and children led by Sinnion entered Empire service and were settled in Thrace.

Sinnion was a veteran of Belisarius expedition against the Vandals at their Vandal Kingdom in North Africa in 533. Noted for their strength and bravery, Sinnion and Balas led a group of 600 Massagetae auxiliares (all mounted archers), at the Battle of Ad Decimum (September 13, 533).