Tardu declares himself to be ruler (khagan) of the united Turkic Khaganate (east and west) in 599.

His new status is not recognized widely in the empire.

Probably to persuade the kurultay, he begins a campaign against China, but unlike the Turks of the eastern part of the Khaganate, his target is too far away and his army suffers intensely from the poisoned waterwells during the long expedition through the steppes.

Finally, he has to retreat without having forced serious combat.

This defeat is disastrous for him.

After a rebellion of his subjects, he will disappear from the scene (probably killed) in 603 or 604.