Donquixote Pirates

The Donquixote Pirates, also known as Donquixote Family (ドンキホーテ ファミリー), is a group led by Donquixote Doflamingo, who goes by the underworld broker alias "Joker".

Past
Not much is known about the Donquixote Pirates before the timeskip, as the term itself did not come up until after. However, Trafalgar Law was once a subordinate whom Doflamingo treated as a younger brother before his defection. Vergo was apparently the first member of the crew, and Law's senior, but before becoming famous, he enlisted in the Marines to serve as a spy on behalf of Joker. The Bellamy Pirates also swore their allegiance to the crew, and was permitted to use its Jolly Roger; Doflamingo dismissed them when their captain was defeated easily, falling out of the expected standards.

At some time, Doflamingo formed a three-way alliance with the rogue Marine scientist Caesar Clown and one of the Yonko, in order to create SAD and SMILE artificial Devil Fruit, to create an army of Zoan-class users within the New World. However, needing Caesar for the SAD production and not trusting him, Doflamingo assigned Vergo and Monet to act as an intermediate and spy/guard, respectively.

Battle of Marineford
While Doflamingo himself participated in the Battle of Marineford, Law, having already formed his own crew and became an infamous rookie, came near the end of the war in order to rescue Monkey D. Luffy. Law succeeds in saving Luffy while Doflamingo emerges from the war unharmed. One year later, Law became a Shichibukai by turning in 100 hearts from pirates and sought shelter in Caesar's hideout, Punk Hazard.

Punk Hazard Incident
During the events in Punk Hazard, Law revealed his rebellion against the Donquixote Pirates by attacking the SAD production room and attempted to kidnap Caesar. Doflamingo ordered Vergo to brutally eliminate Law, but Law succeeded in defeating his senior and, indirectly, killing Monet. Doflamingo, in turn, sent Baby 5 and Buffalo to clean things up and retrieve Caesar, and, upon seeing that Monet failed to detonate the island's chemical weapon as ordered, decided to enter the island himself. However, Baby 5 and Buffalo are swiftly knocked out by the Straw Hat Pirates.

Crew Strength
The Donquixote Pirates is a very powerful crew, as their captain is a world famous pirate and a member of the Shichibukai with a former bounty of 340,000,000. Crew members Monet, Baby 5, and Buffalo are all known Devil Fruit users, while Vergo is a mole who has ascended the Marines ranks for about fifteen years, eventually becoming a vice admiral, while keeping his true identity hidden from everyone outside of his affiliates. They are in charge of the underworld brokering (including slavery, and production and distribution of weapons of mass destruction) in the New World, making them both very influential and very powerful. They are known to have destroyed entire towns at whim, as stated by Baby 5. The crew once also consisted of Trafalgar Law, a powerful pirate rookie who would become a Shichibukai as well with a former bounty of 440,000,000, prior to him leaving for his own interests.

Other Information
The Donquixote Pirates is a very powerful crew in both strength and influence. Being connected with the underworld, they have formed many alliances, ranging from brokering to spies within the Marines. They also managed to recruit significant individuals and entire pirate crews to become their allies, such as Caesar Clown and the Bellamy Pirates. Prior to the latter's dismissal, Bellamy and his crew were attempting to recruit promising pirates for the "New Age" under the Donquixote Pirates' insignia. The crew also formed an alliance with one of the Yonko to create an army of artificial Zoan-class Devil Fruit users, which involves the SAD that only Caesar could produce.

In terms of interpersonal relationships, Doflamingo values the members of his crew somewhat like a family, albeit with tendencies of harsh punishments for failures; he saw Law and Baby 5 as though they were younger siblings, but demanded the former's death in the most brutal fashion possible for treason. He also abandoned Monet and Vergo when they were defeated, going as far as to order them to commit a suicide-bombing to take down all evidence and enemies within, though expressed his sincere regret for forcing them to do so; in turn, both Monet and Vergo, at least, were glad to give up their lives for Doflamingo, and happily bid him farewell. Doflamingo also treasures his alliance with Caesar, if only for the scientist's ability to produce SAD, but has no patience for other allies who fail to meet his standards, as he tortuously discarded the Bellamy Pirates and disowned the Human Auctioning House for respective reasons.

Similar to the Straw Hat Pirates and Big Mom Pirates, the Donquixote Pirates seem to have a wide and randomized variety of crew members, as opposed to many crews that follow a specific theme, ranging from a young girl to elderly people.