D. Ruled a kingdom including most of modern-day France, the Low Countries and western germany.
Shortly after the fall of the roman empire, which was not actually a complete fall cause the system of govern was still working in constantinopla.
Nontheless problems with the succession of power shortly after the king die diveded the Merovingian dinasty and created problems.
They were the one that introduced Christianity to western Europe when the king baptized to obtain recogniton from the Catholic Church.