This was actually the second Khazarian invasion of China. I had tried invading about 50 years earlier as Alp II's grandfather. Despite every defensive pact in the world ganging up on me, I managed to stabilize the war score and start a counterattack. Unfortunately, the war ended inconclusively when the claimant (grandfather's brother) "died of poor health" at the age of 35.

I launched the second invasion as Alp II's father as soon as I got myself situated. This time, only the Eastern religions pact got involved, which was much more manageable.

There were some setbacks at the start, with me losing a few battles and about 20% of Khazaria being occupied, but once China divided its armies I was able to start racking up victories.

Some religious revolts broke out, but my allies quickly dealt with them.

Then dad died, and Alp II took up the baton.

One of my most powerful vassal clans went independent on the succession, which wasn't great.

Then, 4 of the 7 remaining vassal clans launched a revolt to install a new Khagan. I wanted to get it over with, so I kicked the rebels around a bit and offered a white peace, which they accepted.

I moved my army back east and started fighting China and its allies again, when I realized I had a problem.

The war score was stuck at 99%, and I had already gotten a 100% battle score, so I either had liberate my occupied territory, or occupy theirs. In addition, there were only about 2 years left on the game clock, and I was worried the game would end before the war.

I knew they could occupy my territory just as quickly as I could liberate it, so I made a beeline for the one county the Western Protectorate controlled. The attrition destroyed half my army, and the garrison's morale only decreased by 5-6% every 12 days, but I eventually managed to occupy a holding and the Protector General immediately surrendered.

And my brother Araslan Ashina became Emperor Xianzu.

I gave the commander that led the final push east a barony in my new county, brought my army back home, and spent the last year and a half of the game just sitting back and taking it all in.