Sentinel Prime (ROTF)

The name or term "Sentinel Prime" refers to more than one character or idea. For a list of other meanings, see Sentinel Prime (disambiguation).

Sentinel Prime led an expedition! And was a Prime!

It took him fourteen galactic convergences to get an echo of something, apparently. He would presumably be one of the guys that The Fallen turned on, and died in the resulting battle. Revenge of the Fallen Adaptation