Background: The French (French: Francais) are an ethnic group and nation who are identified with the country of France. This connection may be legal, historical, or cultural. Historically the French people's heritage is diverse, including populations of Gauls, Ligures, Latins, Franks, Iberians, Alamans and Norsemen. France has long been a patchwork of local customs and regional differences, and while most French people still speak the French language as their mother tongue, languages like Norman, Occitan, Catalan, Auvergnat, Corsican, Basque, French Flemish, Lorraine Franconian, Alsatian and Breton remain spoken in their respective regions.
Context: With the decline of the Roman Empire in Western Europe, a federation of Germanic peoples entered the picture: the Franks, from which the word "French" derives. The Franks were Germanic pagans who began to settle in northern Gaul as laeti, already during the Roman era. They continued to filter across the Rhine River from present-day Netherlands and Germany between the third to the 7th century. At the beginning, they served in the Roman army and reached high commands. Their language is still spoken as a kind of Dutch (Flemish - Low Frankish) in northern France (Westhoek) and Frankish (Central Franconian) in German speaking Lorraine. Another Germanic people immigrated massively to Alsace: the Alamans, which explains the Alemannic German spoken there. They were competitors of the Franks; that's why, in Renaissance times, it became the French word for "German": Allemand.  By the early 6th century the Franks, led by the Merovingian king Clovis I and his sons, had consolidated their hold on much of modern-day France, the country to which they gave their name. The other major Germanic people to arrive in France (after the Burgundians and the Visigoths) were the Norsemen or Northmen, (which was shortened to Norman in France), Viking raiders from modern Denmark and Norway, who settled with Anglo-Scandinavians and Anglo-Saxons from the Danelaw definitely in the northern region known today as Normandy in the 9th and 10th century, and which was given in fiefdom of the kingdom of France by king Charles III. The Vikings eventually intermarried with the local people, converting to Christianity in the process. It was the Normans who, two centuries later, would go on to conquer England and Southern Italy.  Eventually, though, the largely autonomous duchy of Normandy was incorporated back into the royal domain (i. e. the territory under direct control of the French king) in the Middle Ages. In the crusader Kingdom of Jerusalem, founded in 1099, at most 120 000 Franks (predominantly French-speaking Western Christians) ruled over 350,000 Muslims, Jews, and native Eastern Christians.
Question: How far did the Frankish Kingdom spread?. Whats the answer?
They continued to filter across the Rhine River from present-day Netherlands and Germany between the third to the 7th century.