Håndfæstning (da), Håndfestning (no) (former spelling: Haandfæstning), Handfeste (de), (Eng. transl. handbinding) were names for documents issued from the 13th to the 17th century in Scandinavia and Germany (Prussia), e.g. the charters that were signed by Danish and Norwegian kings, and sometimes also by Swedish kings. In many ways it is a Scandinavian parallel to the English Magna Carta, and it is not unlikely that it has been inspired by the latter.
The håndfæstning was the result of the strength of the power of the nobility. The first Danish king who was forced to sign this kind of charter was King Eric V in 1282. It was used as a regular coronation charter for the first time in 1320. Between 1440 and 1648 it was a normal condition for the recognition of a new king. When absolute monarchy was introduced in 1660 the last håndfæstning was mortified.
Unlike in England there was no permanent charter to sign; every new king had to accept a new one that applied to his own reign. On the other hand all håndfæstninger were based on the same model. The king had to promise that he would rule as a just king; that he would co-operate with the nobility; that he would never imprison any free man; that all leading offices (what one would today call "cabinet minister posts") and all local administration would be filled only by noblemen; and that questions of war and peace depended on the acceptance of the nobility.
The charters did not necessarily transform the kings into puppets; most of them were able to create a solid base of power during their reign. And hardly any Danish king of the period totally kept the rules of the håndfæstning. The severity of the demands of the nobility also wavered from time to time.
Some modern historians have regarded the håndfæstninger as (primitive) predecessors of the modern constitutions. This might be true as for the limitations of the royal power but it would not be fair to call them real democratic constitutions. First of all their purpose seems to have been to secure the power of the nobility and they expressly tried to keep commoners and other people of "low birth" away from any kind of political influence. Unlike their English parallel they therefore do not seem to have inspired any kind of modern Danish constitutional theory.