Regulated duel settled in a confined space, often an islet.

Holmganga was a legal institution in Old Norse society that resolved disputes over honour, property, or defamation. A combatant who refused was considered a niding.

The duelling ground was marked with ropes or stakes and participants were allotted a set number of shields. Professional challengers, notably berserkers, sometimes abused the institution to extort property.

Attestations

Egils saga Skalla-Grímssonar (ca. 1240)
Several holmgangs are described in detail, including Egill's own participation.