The formation of dikes for the protection of lands formerly submerged was already well understood, and regulated by uniform custom.

The plains thus reconquered from the waters were distributed in portions, according to their labor, by those who reclaimed them, except the parts reserved for the chieftain, the church, and the poor.
This vital necessity for the construction of dikes had given to the Frison and Flemish population a particular habit of union, goodwill, and reciprocal justice, because it was necessary to make common cause in this great work for their mutual preservation.
In all other points, the detail of the laws and manners of this united people presents a picture similar to that of the Saxons of England, with the sole exception that the people of the Netherlands were milder than the Saxon race properly so called--their long habit of laborious industry exercising its happy influence on the martial spirit original to both.

The manufacturing arts were also somewhat more advanced in this part of the continent than in Great Britain.

The Frisons, for example, were the only people who could succeed in making the costly mantles in use among the wealthy Franks.
The government of Charlemagne admitted but one form, borrowed from that of the empire in the period of its decline--a mixture of the spiritual and temporal powers, exercised in the first place by the emperor, and at second-hand by the counts and bishops.

The counts in those times were not the heads of noble families, as they afterward became, but officers of the government, removable at will, and possessing no hereditary rights.