On Oct. 29, 1863, the delegates at the Geneva International Conference, also called the first conference of the International Committee for Relief to the Wounded, signed the final resolutions of the conference. Article 8 states:

They shall wear in all countries, as a uniform distinctive sign, a white armlet with a red cross.

The Geneva International Conference (which included 18 official delegates from 14 nations) was followed one year later by the first Geneva Convention, to which 16 nations sent delegates. That convention was intended "for the Amelioration of the Condition of the Wounded in Armies in the Field," and its recommendations were widely taken up.

These conventions took place at a time when Western nations were greatly interested in setting down "rules of war" and guidelines by which noncombatants and the injured would be protected. In the middle of the 19th century, the misery of the Crimean War was followed by the brutal fighting of Italian Unification and the American Civil War.

In 1859, a Geneva resident named Henry Dunant watched as thousands of injured men died of their wounds after the Battle of Solferino. He believed many, if not most, of them could have been saved had they simply received medical treatment. Three years later, he published A Memory of Solferino, which became a European bestseller.

In addition to an account of the battle, Dunant made the case for the establishment of relief societies in countries around the world. These societies would aid the injured and noncombatants. In 1863, the Geneva Society of Public Welfare took up Dunant's ideas, and its resulting committee became the International Relief Committee for Injured Combatants.

This was the organization that convened the 1863 international conference that came up with the symbol. Twelve years later, in 1875, that symbol had become so synonymous with aid that the International Relief Committee changed its name. It became the International Committee of the Red Cross, and that name has been used ever since.

One year after the ICRC assumed its modern name, the Ottoman Empire announced that it would use the red crescent instead of the cross to mark those who cared for the wounded. The cross was offensive to Muslim soldiers, they thought, and so the cross had a cousin.

In the years that followed, other red symbols were created. Iran used a red lion backdropped by a sun until 1980, and Israel has used a red Star of David to mark its aid workers. In December 2005, the Swiss government hosted a conference that adopted a new, nonreligious symbol ─ a red diamond ─ that is officially called the red crystal.