League of Assassins

Doctor Ebeneezer Darrk
The League of Assassins was founded by Ra's al Ghul (exactly when is unknown) to be "the fang that protects the head" (Batgirl #67, 2005). Members of the League demonstrated willingness to die at a word from Ra's. They have included some of the most dangerous assassins in the world including Lady Shiva, David Cain, and master archer Merlyn. For much of its current history any member to fail in an assassination was in turn targeted by the League (and indeed, one of its best-known members, the master-archer Merlyn was eventually forced to flee from the League, fearing for his life, having failed to assassinate Batman). In more recent years this policy has apparently relaxed somewhat.

Ebeneezer Darrk, aka Doctor Darrk, was the first known individual assigned to head the League of Assassins by Ra's al Ghul. Darrk himself was seconded by The Sensei, a martial arts master from Hong Kong. Although many of the League's leaders over the years have been accomplished martial artists, Daark himself did not depend on physical prowess, and as an assassin he instead relied upon careful planning and manipulation, ambushes and death traps, as well as a variety of cleverly concealed weapons and poisons. Although the League apparently had an inner circle of elite fighters as well as a large number of warriors trained in the martial arts, the League during Daark's tenure as leader reflected his personal methodology. Following a "falling out" with Ra's (the exact details of which were never made clear) Darrk kidnapped Ra's daughter, Talia Al Ghul. Batman became involved in this matter while attempting to bring the League to justice for a number of recent killings. Although he had connected the League to several assassinations over the years, all previous attempts to investigate had met dead-ends. Batman rescued Talia (the first time the two would meet, laying the foundation for all their future interaction) and Darrk died while trying to kill them.

The Sensei
Under the direction of the organization's second known leader, the villainous Sensei, the League became more brutal, and rebelled against Ra's' rule. Although The Sensei's methods closely resembled Darrk's, and the majority of the League's operatives showed little to no real skill in personal combat, The Sensei did show slightly more reliance on skilled martial artists. This version of the League is best known for two assassinations. As part of an initiation process, the operative known as the Hook was assigned to murder Boston Brand (who became Deadman after his death). Additionally, Professor Ojo successfully brainwashed Ben Turner (best friend and partner of Richard Dragon), creating an alternate personality dubbed The Bronze Tiger, and turning the master martial artist into a League operative. As The Bronze Tiger, Turner defeated Batman in personal combat while another League operative murdered Kathy Kane (the secret identity of Batwoman in pre-Crisis continuity, and a close personal friend of Batman's post-crisis). Eventually Turner's training at the hands of The O-Sensei proved too strong for the League to fully break, and when he refused to kill Batman he was forced to flee the League. Not long afterwards, the insane Sensei - no longer motivated by anything but a desire to raise assassination to an art - attempted to cause an artificial earthquake in order to kill a number of diplomats gathered for peace talks. Batman traced Ben Turner to a hospital, foiling a League attempt to assassinate the man. Turner could not fully remember the actions of his alternate personality (although years later, as a member of the Suicide Squad, he would reveal that the League had used him to kill a number of people) but he was able to aid Batman in uncovering The Sensei's latest plot. Although Batman was unable to prevent the earthquake, ultimately it was only The Sensei himself that died in the disaster, and control of the League returned to Ra's.

Role in the creation of Lady Shiva
It was more recently revealed that, prior to the betrayals of Doctor Daark and the Sensei, Ra's had grown tired of the fickle loyalties of his warriors. Ra's assigned David Cain to create a perfect bodyguard ("The One Who Is All"). After early attempts to raise such a person resulted in hopelessly psychotic children, Cain decided that he needed a genetically suited child and began searching for a possible mother. To this end he assassinated Carolyn Woosan/Wu-San, one of two astonishingly talented martial artist sisters he had seen fighting in an exhibition. Carolyn's sister, Sandra, swore revenge and tracked Cain down, only to be subdued by the combined might of the League. Both intoxicated and frightened by the levels of skill she was attaining now that she was no longer holding back for her sister's sake, Sandra agreed to be the mother of Cain's child. In return, the League spared Sandra's life, and assisted her in further training. By the time Sandra gave birth she had surpassed the entire League in skill. She left immediately following the birth of her daughter, Cassandra Cain, rechristening herself Lady Shiva.

Other stories would suggest that at some points afterwards Shiva worked as a member of the League, and eyewitness testimony from former League member Onyx indicates that she kept in contact with the League, although she apparently did not see her daughter. Although most of her appearances over the years show her working independently, she apparently had some degree of League membership, and was called upon by Ra's to "rescue" Talia during the Hush storyline.

In keeping with Ra's and Cain's plans, the League attempted to train Cassandra Cain from birth to be the ultimate assassin, unknowingly giving her the skills she would use as the hero Batgirl.

Nyssa al Ghul
After the death of Ra's, his first born daughter Nyssa Raatko formed a new League. Lady Shiva was recruited to serve as Sensei to this incarnation of the League, with the intent that Batgirl (Cassandra Cain) would lead the warriors themselves.

Reflecting Shiva's emphasis for martial arts, the known members of Nyssa's League were all skilled in this area, and included the warriors Shrike, Kitty Kumbata, Wam-Wam, Joey N'Bobo, Tigris, Momotado, Krunk, White Willow, the twin warriors Los Gemelos, Ox, "The Mad Dog", Alpha, and Cristos. The new League was present when Mr. Freeze's wife Nora Fries was brought back to life as the monstrous Lazara, and several members died in the resulting chaos.

Due to the conflict between their loyalty to Shiva and Nyssa and their near-worship of Batgirl as "The One Who is All", the League split at that point, with Ox, White Willow, and Tigris pledging themselves to Cassandra. Several more members of the League (including all the defectors except Tigris) died when the insane "Mad Dog" went on a killing spree. "The Mad Dog", it was revealed, had been one of David Cain's early attempts to create Ra's' perfect warrior. The Mad Dog had been considered useless as a child, since Cain's methods had driven him murderously insane, and Ra's had ordered the child be killed. Nyssa, however, knew that the servant ordered to carry out this execution had instead released him into the wild, explaining how it was possible to recruit him. The Mad Dog was successful in killing Batgirl (who gave her life to protect the burqa-clad assassin Tigris). She was quickly restored to life in a Lazarus Pit by Shiva, in order that the two could face each other in a final battle. Batgirl won leaving Shiva on a meat hook suspended over the Lazarus Pit.

Several factions
Although most of its members had died or defected, the League survived the Infinite Crisis, and was seen to play an important role in The Society's world-wide prisonbreak. Throughout the period of aftermath it remained under the control of Nyssa, until she was apparently killed in a car explosion. Cassandra Cain has apparently taken over the League as its new leader, although she abandoned the league at some point prior to the Teen Titans storyline Titans East, where it is revealed that she was being drugged by Deathstroke.

Furthermore, it appears that Cassandra was battling for complete control of the League of Assassins with Ra's Al Ghul's youngest daughter Talia, as well as the Sensei. Talia who would naturally assume control of her father's empire by default following Nyssa's death, has recently been seen in the Batman & Son storyline, leading ninja members of the League of Assassins, against Batman. At the same time, several members felt neither Talia nor Cassandra were up to the role, and, after failing to recruit Black Canary's adopted daughter Sin, gave the leadership to the Sensei, who recently reappeared in the Resurrection of Ra's Al Ghul storyline.

In the One Year Later event, Talia later forced Kirk Langstrom to give her the Man-Bat formula which she used to turn some of it's members into Man-Bats.

In the series Green Arrow/Black Canary #11 a metahuman faction of the League of Assassins was introduced. They were involved in the abduction of an injured Connor Hawke. This groups members included Bear (a Mexican yeti-like man), Tolliver (a vampire), Ruck (a four armed gunman), Spike (a female martial artist capable of creating energy blades), Mazone (a bearded Samurai), and their leader Targa (a telekinetic little person). However, although they thought they were being commanded by Ra's al Ghul, they were apparently duped by an imposter, Shado.

Television

 * In Batman: The Animated Series, Ra's led the Society of Shadows. It first appeared under the control of a character loosely based on Count Vertigo, simply called "Vertigo", who filled a role similar to that of Ebeneezer Darrk, but he was killed in the same episode that introduced him through a scheme of Ra's al Ghul's (who finally appeared at the very end).
 * Interestingly, in the comic book Batman: The Gotham Adventures (based on Batman: The Animated Series), it was revealed that the League of Assassins existed as a separate entity from the Society of Shadows (although both groups served Ra's al Ghul). Much like their counterpart in the mainstream DC Universe, this version of the League of Assassins was responsible for the murder of Boston Brand, creating the ghostly hero Deadman (which might make the events canon in the DC animated universe, since Deadman's murder was referenced in that continuity). The Sensei, however, was loyal to Ra's in this continuity, and faced with either living out the last of his years in prison or defying Ra's wishes, he chose a third option: suicide.
 * In the future of Batman Beyond, Terry McGinnis (the future Batman) confronts Curaré, the deadliest member of the Society of Assassins, now a guild of Ninja assassins for hire in the future. Terry and an elderly Bruce Wayne later battle against the League of Shadows when Ra's Al Ghul (who had taken over Talia's body) attempted to take Bruce's body. It's also known as the Society of Shadows.

Batman Begins'
See: League of Shadows