- "The Key is the link... the link must be severed... such is the will of God"
- ―Knights of Byzantium motto[src]
The order was created at an unspecified time in the past, although it is implied by their cause and actions that they were formed around the time Glory arrived on earth or started to seek the Key. Since their formation, they began to seek the Key and pledged to destroy it. Around the same time the Knights began to look for the Key, a group of monks called the Order of Dagon also sought the Key, although the monks sought to preserve and defend it. The Knights failed to get to the Key before the monks did and thus sought the new form the Key was shaped into.
In the early 2000, the knights eventually located the Key to Sunnydale. Although initially they were not sure on who or what the Key became, they knew that it was sent to the slayer for protection. They sent a few of their members to retrieve the Key from the slayer, but they were thwarted by Buffy Summers and Glory on different confrontations. The knights claimed that they could easily send more knights if needed. One of the knights, Orlando, was captured, tortured and consumed by the hell-goddess, causing him to be mentally unstable.
Later on, the order arrived in full force, led by the General Gregor. Dante Chavalier and other knights took Orlando from the mental ward back into their ranks and used him to locate the Key. Upon seeing the insane Orlando, who revealed that the Key was turned into a human girl, Gregory declared ending the conflict and mobilized the entirety of their army present in Sunnydale.
The Scoobies, who were fleeing town, used a trailer for transport. The knights tracked them down using a contingent of knights mounted in horses. The cavalry was successful in taking down the trailer and fatally injuring Giles at the price of ten men. The Scoobies were forced to take shelter in a deserted gasoline station, where later on, the knights renewed their attacks. They were close to breaking open the barricade set up by the Scoobies until Willow conjured a force field to stop their attacks. In the battle that ensued, Gregor was captured and taken hostage. Dante called on the order's clerics to bring down the wall. Later, Buffy attempted to negotiate with the knights in allowing Ben to attend to the wounded Giles. This proved detrimental as Ben later lost control and changed into Glory, who massacred Greg and later, all the knights and clerics in the area.
While the Knights ultimately failed, Buffy and her gang managed to defeat and kill Glory themselves.
The knights considered themselves to be very devout and fiercely believed they were doing God's will. They looked down on witches and call them infidels. They were steadfast and were unyielding in their beliefs--they followed their motto regardless of the Key taking a human form. Dante killed his brother-in-arms Orlando to prevent the insane knight from serving Glory.
To demonstrate their allegiance to the Order and their rank within it, they bore tattoos on their foreheads. They also had a preference for wearing twelfth century clothing and armor, and using medieval weapons.
Hierarchy and StructureThe knights considered each other to be brothers. They were led by a General, who commanded the entire army's actions. The knights weilded various weapons, although most of them fought with close-combat weapons such as swords, axes and flails. Some knights acted as archers, using crossbows, longbows and flaming arrows to attack from range. Other knights were mounted on horses and acted as the cavalry. The order also employed clerics to work spells and incantations.
Orlando claimed that his brotherhood could send thousands of men, although the entire number comprising the order was never stated. All of the knights and clerics present in Sunnydale were killed by Glory.