Where does “Heraclius” come from?

Heraclius is the Latin form of Ancient Greek Ἡράκλειος, a name derived from the Greek hero Heracles, though its precise original meaning remains uncertain.

Ancestry of “Heraclius”, step by step

Step	Language	Word	Meaning
1	Latin	Hērāclīus	—
2	Ancient Greek	ἡράκλειος	—
3	Ancient Greek	Ἡρακλῆς	Heracles
4	Ancient Greek	-κλῆς	An element found in given names
5	Ancient Greek	-κλέης	—
6	Ancient Greek	κλέος	rumour, report; good report, fame, glory; bad...
7	Proto-Hellenic	kléwos	fame
8	Proto-Indo-European	ḱléwos	fame
9	Proto-Indo-European	ḱlew-	to hear
10	Proto-Indo-European	ḱel-	to cover; to incline

Every word from Proto-Indo-European ḱel- →

Heraclius — Etymology, Origin & Word History | Etymology Explorer