After the defeat of
Saxony (772–804) the empire of
Charlemagne extended to the mouth of the Elbe and beyond. By this time at the latest, the first contacts with the Vikings who, like the Saxons, worshipped
pagan gods, took place. ) These contacts were often
warlike in nature. The Frisian islands were affected as well as the Frisian mainland. To ward off the attacks, Charlemagne set up a
march on the northern border of his empire, the name of today's state of
Denmark being derived from it. Despite the warlike situation on the northern border, many Vikings were used as
mercenaries in Frankish campaigns. The Vikings were bold raiders, perhaps because of the
code of honour they are purported to have had, According to legend, the
god of war,
Odin, from the
Asa line of gods, prepared to fight for the world and its survival. He sent his messengers, the
valkyries, to escort the bravest warriors killed in a battle to
Valhalla. The warriors who gathered there, called
Einherjar, practised the art of warfare during the daytime. In the evening, after their wounds had healed, the army of the dead moved into Odin's hall together, where there was always a filled drinking horn and a good meal. Whether this code of honour existed or not, much of their fighting was, in any case, against civilian populations and weakly defended towns and monasteries. One of the first Viking kings to be baptized was
Harald Klak who, in 826, became a vassal of King
Louis the German at
Ingelheim am Rhein and was baptized in Mainz with his wife and son. During this time, the
Vikings attacked the
Frankish Empire sailing their ships up the big rivers from the
North Sea and
Atlantic Ocean. Such raids mainly affected areas on the
Seine and in modern-day
Netherlands and
Belgium. Previously, the Vikings had raided England (
Lindisfarne, 793) and Ireland (
Dublin, 795). In 820, the first major attack by Vikings on the Frankish Empire was recorded, taking place around the mouth of the river Seine, and at the same time other Vikings probably invaded Flanders. In 845,
Paris was attacked for the first time with about 700
longships up the Seine. The Parisians bought the raiders off with 7,000 pounds of silver. By 926, thirteen of these payments have been documented in the Frankish Empire. The Elbe estuary and the already fortified city of
Hamburg were attacked by Danish warriors in 845. Initially, the attacks took the form of raids and the Vikings withdrew to their homeland afterwards. In the 860s, they changed tactics and established permanent bases in
Francia, from where they coordinated their raids, and sometimes overwintered in their fortified army camps. The
Rhineland, the heartland of the Frankish Empire, was little affected by the Vikings at that time. The Vikings were not a united people, but a collection of warring tribes; small wars between Viking tribes were frequent, united large-scale attacks were preceded in principle by purposeful diplomatic negotiations. Since the Vikings could only be driven out of the occupied territories at great cost, attempts were occasionally made to involve their leaders in the Empire by means of rich gifts and the granting of
fiefdoms. As a rule, these Viking leaders were expected to be baptized beforehand, since the Frankish empire was considered by the Frankish
nobility to be a gift from
God and so there were no thrones for higher nobles who were unbelievers. == Raids of 862 and 864 ==