🏛️ Ancient and Medieval Roots (Before the 19th Century)

 

Early limits on warfare were generally rooted in custom, military codes, religion, or philosophy, rather than formal treaties between nations.

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• Ancient Codes: Rules can be found in the Code of Hammurabi (Babylon), the Hindu Code of Manu (prohibiting poisoned or barbed weapons), and even in the Old Testament (limiting the destruction of fruit trees during sieges).

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• "Just War" Doctrine: Developed by figures like St. Augustine and Thomas Aquinas, this doctrine provided moral and philosophical criteria for when it was permissible to go to war (Jus ad bellum) and how the war must be fought (Jus in bello).

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• Chivalry: In medieval Europe, codes of chivalry provided protections for noble prisoners and non-combatants, although these rules often did not extend to common soldiers or peasants.

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• Hugo Grotius (17th Century): The Dutch jurist is considered the "father of international law." His 1625 work, De Jure Belli ac Pacis (On the Law of War and Peace), provided a secular, systematic framework for the laws of war, influencing state practices for centuries.

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📝 The First Modern Codifications (Mid-19th Century)

 

The advent of massive, industrialized armies and increasingly destructive weapons in the mid-19th century created an urgent need for written, official, and universal rules.

 

1. The Lieber Code (1863)

 

• Context: American Civil War (1861–1865).

• Significance: Drafted by jurist Francis Lieber and issued as General Orders No. 100 by President Abraham Lincoln for the Union Army. It was the first modern, comprehensive codification of the laws of war for an army in the field.

• Key Topics: Military necessity, martial law, treatment of prisoners of war (POWs), treatment of civilians, and spies. Its principles heavily influenced all subsequent international codification efforts.

 

2. The First Geneva Convention (1864)

 

• Catalyst: The Battle of Solferino (1859), which witnessed horrific suffering and a complete lack of organized care for the 40,000 wounded soldiers. Swiss businessman Henri Dunant was appalled and proposed:

  1. Creating national societies to help the wounded (later the Red Cross).

  2. Drafting an international legal treaty to protect wounded soldiers and those who care for them.

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• Significance: This landmark treaty, The Convention for the Amelioration of the Condition of the Wounded in Armies in the Field, established the principle of neutrality for military hospitals and ambulances and their staff, regardless of which side they served. It also adopted the Red Cross as the distinctive protective emblem. This was the birth of what would become the "Geneva Law" side of International Humanitarian Law.

 

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⚔️ Limiting the Means of Warfare (Weapons)

 

Simultaneously, states began adopting limits on the methods of war.

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• St. Petersburg Declaration (1868): This was the first formal agreement prohibiting the use of a specific weapon. It renounced the use of explosive or incendiary projectiles under 400 grams, asserting that the only legitimate object of war is to disable the enemy's military force, and weapons that cause "unnecessary suffering" should be banned.

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🌍 The Hague Conventions (1899 and 1907)

 

These two international peace conferences are the foundation of the second major branch of IHL, often called the "Hague Law," which focuses on the conduct of hostilities.

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• Focus: Regulating the means and methods of warfare (how to fight) and the rights and duties of belligerents.

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• Key Achievements:

  • Prohibited Specific Weapons: Banned the use of asphyxiating gases (1899) and "dum-dum" (expanding) bullets.

  • Laws and Customs of War on Land (Hague IV): Established rules for military occupation, the definition of a lawful combatant, the prohibition of pillage, and the protection of historic monuments.

  • Pacific Settlement of Disputes: Created the Permanent Court of Arbitration (PCA).

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➡️ The Final Steps

 

• Geneva Conventions of 1929: After the horrifying trench warfare of World War I, which exposed weaknesses in the existing rules, new conventions were adopted. They significantly improved the treatment of Prisoners of War (POWs) and the wounded and sick.

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• The 1949 Geneva Conventions: The ultimate codification came after the atrocities of World War II. The four Conventions were comprehensively revised, and most importantly, the Fourth Convention was added to specifically and extensively protect civilians—the group that suffered the most during the war.

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The journey from Grotius to the 1949 Conventions was a steady movement from theory and custom to legally binding, universal treaties, driven by the increasing scale and horror of modern warfare.