During the 14th century, it became quite fashionable for kings and magnates to establish "Orders of Chivalry." Some of these still survive in England. These were not merely high honors. The members of the order were normally expected to stand with the master in battle, as did Sir Thomas Erpingham, chief of the archers at Agincourt.

Order of the Garter 1348,

The Origin
The most Noble Order of the Garter was founded by King Edward III in 1348. Its origins and the reason for its foundation much like King Arthur's Roundtable remain a mystery to this day. It is believed that the order was begun after the king attended a Ball where he found a garter belonging to a certain fair lady. Having his guards laughing at him he replied that this garter would become the highest honor in the land, a promise he was to fulfill.

Making it the motto of the order.
It is believed the king found the blue garter tying it around his own leg while speaking
"Honi soit qui mal y pense" - "Shame on him who thinks ill of it."
He was to hold the first formal Garter ceremony on 23 April at St. George's Chapel. The original members of the Order were all friends of the King and his heir although not necessarily of royal blood but certainly military heroes. Among the members were Waltery Manny, Henry of Lancaster, Ufford of Suffolk, Sir John Chandos and Richard of Arundel among others.
Members of Garter were all dressed in robes of blue, the royal blue of France, quite fitting after his great victory
From the earliest times ladies were received into the Order as "honorary members" but this practice died out under Henry VIII. It was not until the reign of Edward VII that the King's Consort was automatically a "Lady of the Garter". The Statutes of the Order have recently been amended to allow admission of females as Ladies Companion. The first such admission was that of Lavinia, Duchess of Norfolk, in 1990. Foreign royalty are appointed as "Extra Knights and Ladies of the Garter" and they are in addition to the twenty six Knights or Ladies Companion. Non-Christians cannot become members of the Order.
The Order is the highest English Order of Chivalry and is one of the most important of all such Orders throughout the world. The conferment of the Order entails adoption into knighthood and, for the Knights Companion, the right to use the title "Sir" before their Christian names. Further, the holders of the Order are entitled to add the letters "K.G." or "L.G." after their surnames or title.
The banners and crests of the Knight Companion are hung in the Chapel of the Order, St. George's Chapel at Windsor. A stall plate showing the name and arms of the occupant are attached to each stall. The banners and crests remain above his stall during his lifetime and are taken down at his death. The cost of preparing the banners, crests and stall plates is borne by the Order. The reigning monarch is The Sovereign of the Order, and 23rd April, St. George's Day, is the Day of the Order.

The ribbon around the shield signifies the status of Order of the Garter.

The words Honi soit qui mal y pense mean "Ashamed be he who thinks ill of it."

The insignia consist of the Collar and Badge Appendant known as the George, the Star, the Garter and the Sash with the Investment Badge, called the Lesser George.

The Collar with the George is only worn on Collar Days or on special occasions commanded by The Sovereign. At ceremonies in St. George's Chapel the Knights and Ladies Companion wear the Mantle and Hat of the Order. The Collar with the George is worn outside the Mantle and fixed to the shoulders with white satin bows.