Mighty were the wars of old, in the days when there were no conventions to regulate what was allowed in battle and what was forbidden. The battles and the diseases and infected wounds that broke out afterwards proved such a meat grinder that some armies raised the dead to fight for them, including their own. The raising of freshly dead bodies proved problematic, however. The bodies soon rotted and it caused the disease problem to get even worse. Also many soldiers did not want to serve alongside the dead, and here and there outrage flared up when soldiers saw the husks of their former comrades sent to fight alongside them. So the commanders and the state necromancers took to using skeletons or bodies stripped down to the bare bones. When these proved brittle they took to plating them with iron and so the Ironbones were created. At the same time the opposing wizards were creating spells to destroy them or to turn them against their creators, and there was no time to test these spells first as would be the case in peacetime.
One of these spells worked well but not in the way it was planned. Cast on an advancing Ironbone unit it was supposed to turn them against the opposing army, but instead it ripped their souls from their various destinations in the afterlife and placed them back in their original bodies. As they in life had belonged to an elite unit and were close friends, they recognized each other, and horrified at what had happened to them, fled the battlefield by running in between the two armies.
Despite various arrows and spears hurled at them by both sides, over a hundred of them made it out alive led by what in life had been their captain, Andre Reznichenko. The magics cast on them had enabled them to speak, in case it was needed on the battlefield. Knowing that as Undead they would be hated and feared and that there was no hope of rejoining their families, they decided to flee the country in the hope of finding a faraway place to live in peace far from the horrors of war.
So they headed into one of the few great forests that still stood and headed west, and it was on the way that they came across a king and his entourage being attacked by a large gang of heavily armed bandits. Captain Andre at once came to the kings aid, just as the last of the royal bodyguards died. At the sight of over a hundred Ironbones, the bandits turned and ran screaming for their lives convinced that a demonic army had arisen to drag them down to Hell for their crimes. The king fainted in fright. When he woke he begged for his life, protesting that he had always been a good ruler. Captain Andre replied that he had no intention of harming him, and told him of the strange situation that he and his friends were in.
The grateful king suggested something that would help both them and himself. He would give them citizenship in his country, passports, the legal right to defend themselves against attack, and well-paid jobs as his new royal bodyguards, and they in return would protect him with their unlives. His kingdom was prone in the past to coups where the royal bodyguards had killed the monarch and sized power for themselves, but nobody would accept an Undead skeleton as the new ruler. And if he was overthrown then the new ruler might well decide to exterminate them, fearing them because they were undead.
When they reached the royal capital the courtiers and the people were at first very against the idea but the king told them that he owed his life to these undead and managed to persuade them to accept his idea. Ever since then the Kings Bones, which is what the unit is called, and the royal line that they protect have both kept their side of the bargain. The royal family no longer need to fear assassination from those that guard them, and the Kings Bones, now grudgingly accepted by the vast majority of the population, can live their unlives without being hunted down by vigilantes.
The King’s Bones wear ornate chainmail and plate armour with the royal seal upon their sheilds and breastplates, and carry swords and spears as their weapons when on duty. In peacetime they guard the royal palace and the doors of the royal bedchamber, whilst in war they serve as the personal bodyguards of the king. The kingdom stays out of most wars, seeing them as an expensive waste of time, which suits the King’s Bones fine. They cannot be bribed and if anyone is foolish enough to try they find themselves arrested at once and dragged in front of the king to explain their actions.