The Realm of Kings is a cosmic crossover event in Marvel Comics written by Dan Abnett and Andy Lanning. It covered the aftermath of the Kree-Shi'ar War (The War of Kings), which resulted in the creation of the Fault between the galaxies of the Local Group. Making its first appearance is the Cancerverse, one of the realities conquered by the Many-Angled Ones.
It's the prelude to the Many-Angled One invasion of the prime reality. The event was covered in the one-shot issue of Realm of Kings, the Realm of Kings: Imperial Guard 5-part mini-series, the Realm of Kings: Inhumans 5-part mini-series, issues #20-24 of the 2nd volume of Guardians of the Galaxy, and issues #31-35 of the 4th volume of Nova.