The Blades are members of an elite Imperial order dedicated to the protection and service of the Dragonborn emperors of Tamriel. Descended from the Akaviri Dragonguard, who became the personal bodyguard of Emperor Reman I, the Blades have since diversified into many areas of Imperial espionage, military, and diplomacy. Indeed, while a select few are appointed by the emperor to serve openly as diplomats or bodyguards, the majority of Blades agents act covertly as couriers and spies. Serving as the emperor's eyes and ears, a vast network of Blades have influenced many critical events across Tamriel, such as reassembling the golem Numidium and defeating Dagoth Ur.
The arms, armor, architecture, and customs of the Blades reflect their Akaviri heritage, most famously their distinctive Akaviri katanas and ceremonial armor. The order operates several strongholds, called temples, usually located in commanding positions among the mountains. Known examples include Cloud Ruler Temple in Cyrodiil and Sky Haven Temple in Skyrim.
For more general information, see the main lore article.
 The Blades in Oblivion
Jauffre is the current Grandmaster. When you first bring Brother Martin to Cloud Ruler Temple during the Weynon Priory quest, Jauffre offers to make you a member of the Blades. You can choose whether to accept the offer or decline; if you decline, you can ask Jauffre at any later time about "Join the Blades" and become a member. Jauffre will not offer you membership if his Disposition is below 40, in which case, use a Charm spell to temporarily boost his disposition. Also, Jauffre cannot offer you membership if he dies (which is possible during the quests The Defense of Bruma and Light the Dragonfires). If you want to eventually join the Blades, you may want to be sure to join before those quests or else keep Jauffre alive.
The primary advantage of joining the Blades is that you can use anything in Cloud Ruler Temple (beds, a free horse, free weapons in the Armory, books, etc). You are given an Akaviri Katana upon joining. There is no advancement in this faction, nor are there any associated quests. It is not necessary to join the Blades to complete the Main Quest.
There are three total ranks in the Blades in Oblivion: Knight Sister/Brother, Captain, and Grandmaster. Only the lowest rank is available to the player.
 Blade members in Oblivion
There are two Factions for the Blades. Blades contains most of the NPCs listed above while Character gen Blades contains Baurus, Glenroy and Captain Renault - the three you meet at the start of the game.
* These NPCs are not actually part of the Blades faction, but are included here for completeness.
- Though the Blades are an established authority in the Empire, they do not pursue the common duties of law enforcement: Blades will not arrest you if you are caught committing a crime or if you have a bounty on your head.
- The Order of Talos serves an auxiliary function for the Blades, secretly offering shelter and assistance to traveling Blades as well as providing a way for retired Blades to continue serving the Emperor in a more subdued fashion. A chapter-house of the Order, Weynon Priory, is involved in the Main Quest.