No quarter

Since the Hague Convention of 1899, it is considered a war crime; it is also prohibited in customary international law and by the Rome Statute.

During the First English Civil War, the Long Parliament issued an ordinance of no quarter to the Irish on 24 October 1644 in response to Confederate Ireland electing to send troops in support of Charles I of England against them: An Ordinance Commanding that no Officer or Soldier either by Sea or Land, shall give any Quarter to any Irishman, or to any papist born in Ireland, which shall be taken in Arms against the Parliament in England.

The garrison signaled their intent to surrender by "beating the chamade"; if accepted, they were generally allowed to retain their weapons, and received a safe conduct to the nearest friendly territory.

By promising quarter, pirates avoided costly and dangerous sea battles which might leave both ships crippled and dozens of critical crew dead or incapacitated.

[9] Since a judgment on the law relating to war crimes and crimes against humanity at the Nuremberg trials in October 1946, the 1907 Hague Convention, including the explicit prohibition to declare that no quarter will be given, are considered to be part of the customary laws of war and are binding on all parties in an international armed conflict.