By the time of the First and Second War, warriors clad in heavy armour and on horseback had become powerful units in any modern army. Not only was the concept more glorious than trudging to battle on foot, but the person in question could also move quickly, and trample down their enemies. Should cavalry face cavalry, the sheer force and momentum of the charge would gurantee a violent, exhilarating clash.
One result of the First War was the virtual destruction of the Holy Order of Northshire Clerics, later known as the Brotherhood of Northshire. Historical accounts explain how the clerics, whilst adept in healing, did not possess the necessary skill and equipment to endure when facing an enemy such a destructive force as the Orcish Horde. As such, Archbishop Alonsus Faol and his apprentice Uther (later nicknamed "the Lightbringer") sought to merge a group of priests and knights in order to create a highly skilled, holy order to protect humanity. These paladins would not only become deadly combatants, wielding weapons as well as the Holy Light, but could also be called upon to aid the populace in matters of healing and curing.
A code of behaviour evolved for the paladins, which dictated how they should conduct themselves in matters of faith. Naturally, a sense of honour became closely connected with this code, and unjustified and cruel acts of retribution, violence, and vengeance was shunned. Because of these virtues, paladins were often elevated to high positions within the human kingdoms, controlling land and wealth. Notable examples include Tirion Fordring, who currently leads the Argent Crusade. There were however also cases where paladins did not rise to power because of deeds of valour, but rather due to their status and prestige being based mainly on heredity, of which the former Crown Prince of Lordaeron, Arthas Menethil is a perfect example.
The Code of Honour & the Three Virtues
Today, the Church of the Holy Light permeates nearly every aspect of human society, and its values can thus be taken for granted at times. To the established priesthood and paladins, however, a set of teachings known as the Three Virtues provide the guidelines for proper worshipping and way of living.
The first of these virtues is respect, which dictates that a person should always respect others, even be they enemies on the field of battle. The second virtue, tenacity, is the lesson of knowing the value in persevering in the face of adversity, and be guide by righteous principle. Thirdly, we have the sadly undervalued third tenacity, compassion, which I feel needs no further explanation.
Beyond the Three Virtues, paladins have generally been observed to embody other traits, such as championing justice against evil, defending their homeland, and protect the Church and their faith. In a way, this became a cornerstone of society.
During the Second War, the Alliance of Lordaeron and the Church of the Holy Light gave way to the creation of the paladin. On a more specific note, this entailed the creation of the Knights of the Silver Hand. Becoming a member of this chivalric order was (and remains) extremely prestigious.
During times of war, the Knights of the Silver Hand supported the goals of the Church, and became the fiercest warriors the Alliance could muster. To distinguish members of the order, a system of colours and heraldry was developed, such as the famous Silver Hand itself. In time, as the order grew and its members gained in renown and prowess, many artefacts of the order became holy objects to be revered by those who would follow down the same path. Such objects include the Shroud of Uther and Gavinrad's Sigil just to name a few.
Paladins in Modern Times
There is hardly a person on Azeroth who has not in some capacity felt the devastating effects of the horrific Third War, and arguably one of the organisations suffering most in its wake was the Knights of the Silver Hand. Years before they had lost High General Turalyon, and by the hands of one of their own brethren, Lord Uther the Lightbringer and Gavinrad the Dire now lay dead. The resulting losses from the Scourge's advance could be felt within the hearts of many paladins for years to come, and directly led to the creation of the fanatical Scarlet Crusade. This group bears a significant responsibility for many atrocities in recent times, and many of their members' ultimate fate are probably seen by the Church as divine punishment.
Nevertheless, it would be a sure mark of a fool to dismiss all tidings past the Third War as ill for worshippers of the Light. The knowledge of the Holy Light brought to Azeroth by the Prophet Velen and the draenei vindicators has only proved invaluable in matters of healing and holy warfare. Moreover, the rise of the Blood Knights of Quel'Thalas and the tauren Sunwalkers reminds us that more facets and avenues of the Holy Light have yet to be explored. Despite the former organisation's past reputation of abuse, it is clear from interaction with the blood elves that the order has greatly contributed to a renewal of national, as well as spiritual identity within Quel'Thalas. The full effect of the Sunwalkers on the rest of tauren society remains, as of this writing, unseen.
Most enduring and inspiring amongst the travails of paladins in recent time is the formation of the Argent Crusade, of which volumes could be justly written. Chief amongst their exploits stands their success in the War against the Lich King, in which all of Azeroth's denizens are indebted.