Short answers, pulled from the story.
The Franks were a group of Germanic tribes living near the lower Rhine who acquired a shared collective name during the Crisis of the Third Century, roughly from 235 to 284 AD. Specific tribes such as the Chamavi, Bructeri, and Chattuari were among those identified as Franks. They had been living across the Rhine under Roman hegemony for centuries under various tribal names before adopting the Frankish identity.
The original meaning of the word Frank is uncertain. Leading proposals connect it to a proto-Germanic root meaning fierce or greedy, with descendants in Old English, Old Norse, Middle Dutch, and modern German. The English adjective frank, meaning free or candid, derived from the name of the Franks rather than being its source, because the Franks were regarded as the free people.
Clovis I became the first king of all the Franks in 509, after conquering Cologne. His conversion to Christianity came earlier, in 496, when he was baptised by Saint Remi after a victory over the Alemanni at the Battle of Tolbiac. Gregory of Tours records that over three thousand of his soldiers were baptised alongside him.
Charlemagne was crowned Holy Roman Emperor by Pope Leo III in 800. His coronation was seen in the West as establishing him and his successors as legitimate continuators of the emperors of the Western Roman Empire.
In 870, the Frankish realm was permanently divided between western and eastern kingdoms, which became the predecessors of France and the Holy Roman Empire respectively. The Carolingian Empire also gave rise to Burgundy as a successor state. The division followed Frankish law requiring equal division of inheritance among all living male adult heirs.
During the medieval crusades in the Eastern Mediterranean, the term Frank was applied broadly to any European from western or central Europe who followed the Latin rites of Christianity under the authority of the pope in Rome. This usage spread eastward into many Asian languages, where Frank-related words such as Farang became generic terms for all western Europeans.