"“The Kingsguard is a sworn brotherhood. Our vows are taken for life. Only death relieves us of our sacred trust.” ~Barristan Selmy, Lord Commander of the Kingsguard."
The Kingsguard brotherhood was created some 300 years before the events of Game of Thrones timeline by Aegon I Targaryen , after he conquered Westeros and united the Seven Kingdoms. Aegon assigned the honor of protecting the royal family to seven of the most skilled knights and warriors in the land.
When a knight joins the Kingsguard, he is given a white cloak and enameled golden armor. This isn’t always the case, as the Kingsguard of Aerys II Targaryen wore special silver armor adorned with the three-headed dragon of House Targaryen. But in all cases, the Kingsguard are given raiment befitting their high station.
When a king or queen appoints someone to their Kingsguard or Queensguard, the knight must swear holy vows in the light of the Seven Gods of Westeros. They vow to protect their King or Queen and their family from harm, at all times, no matter the conditions. Much like the brothers of the Night’s Watch, the Kingsquard vow to never take a wife, wear a crown, or father children. They are to live their lives as examples to the rest of the kingdom of how a knight ought to carry themselves: with honor and virtue.
It doesn’t always work out that way, of course. Plenty of Kingsguard members have broken their vows over the years. Jaime Lannister, for example, fathered three children with his sister Cersei and pushed a kid out a window while wearing the white. He even killed the king he was sworn to protect, the Mad King Aerys Targaryen, although in that case there were extenuating circumstances aplenty.
Traditionally, an appointment to the Kingsguard lasts for life, although there are exceptions to this, too. After the death of King Robert Baratheon, his successor King Joffrey and his mother Cersei Lannister removed then-Lord Commander Barriston Selmy of his duties, to make room for Sandor “the Hound” Clegane.
In the 300-year history of the Kingsguard, only one woman has ever served in its ranks, and then only briefly. During the War of the Five Kings, Renly Baratheon — youngest brother of the newly deceased King Robert Baratheon — awarded a position in his Rainbow Guard to Brienne of Tarth, after she defeated the talented Ser Loras Tyrell in a melee. It may have only happened the once, and Renly’s Rainbow Guard wasn’t exactly the same thing as the Kingsguard, but it could establish a precedent for women going forward.
Neither the Hound nor Brienne are knights, but traditionally, only knights are allowed on the Kingsguard. Knighthood is closely associated with the Faith of the Seven, meaning the Kingsguard is, too. That may be why the idea never caught on in the North, where most still keep the Old Gods. When Robb Stark called his father’s bannermen to march on King’s Landing near the start of the War of the Five Kings, his men proclaimed him the King in the North, the first since Torrhen Stark knelt before Aegon Targaryen centuries before. Instead of creating a Kingsguard, King Robb named his most loyal protectors his Battle Guard, one of whom was Dacey Mormont, a female warrior from Bear Island.
Robb is dead, and his bastard brother Jon Snow the new King in the North. So far as we know, Jon hasn’t yet named a Battle Guard. And given recent events, he may not have to. Although he doesn’t know it yet, Jon is actually the trueborn son of Rhaegar Targaryen and Lyanna Stark, meaning he has a legitimate claim to the Iron Throne. Of late, he and Daenerys Targaryen, the daughter of the last Targaryen king and someone else with a solid claim, have grown very close. They may have even fallen in love.
Although Jon and Dany have many hurdles yet to clear — an undead army, for one; the fact that they’re related, for another — one of many ways Game of Thrones could end is with the two of them married and ruling Westeros together, with Jon as King. If that happened, we got to wondering who Jon might appoint to his own Kingsguard. What knights and warriors are talented and virtuous enough to protect Aegon Targaryen, the Sixth of his Name, King of the Andals, the Rhoynar and the First Men, and his family? Time to get creative…