Childeric III died in 754.
Childeric III was born in 717.
Childeric II died in 675.
Childeric II was born in 653.
Childeric I or Clovis I. Childeric can be considered the first king, but Clovis conquered much of the territory owned by the Merovingians.
Nothing special happened to Rome in 750 CE. The pope was Zachary, who was the Bishop of Rome form 741 to 752 . He encouraged the deposition of the last Merovingian king of the Franks Childeric III and Pepin (the initiator of the Carolingian dynasty) to become king. Childeric III was deposed on 752. If you are referring to 750 BCE, 753 BCE was the date of the foundation of Rome.
300 Bees in the Tomb of Childeric
Amoghavarsha III died in 939.
Indra III died in 929.
Ahmed III died in 1736.
Agesipolis III died in -183.
Cleomenes III died in -219.
Jagadhekamalla III died in 1183.