In 1402, Constantine together with the prince Ivane I Jaqeli of Samtskhe submitted to Timur but never took part in the war against Georgia.

He succeeded on the death of George VII as king in 1407 and launched a program of restoration of what had been ruined and destroyed during Timur's invasions.

Towards 1411, he allied with the Shirvanshah Ibrahim I and the ruler of Shaki Sidi Ahmed to counter the Qara Qoyunlu Turkoman advance into the Caucasus.

In the decisive Battle of Chalagan, the allies were routed and Constantine, his half-brother David and the Shirvanshah Ibrahim were taken prisoner.

In the captivity, he behaved arrogantly and the infuriated Turkoman prince Qara Yusuf ordered him, David, and 300 Georgian nobles to be executed.