2000 years ago, the world was overrun with hellish demons. Commanded by the Devil, they killed many and war began with the Human World. A demon named Sparda, however, took a human lover named Eva and fathered two children before rising up against the Devil and sacrificing himself to seal the demons from the Human world. The two children left in Eva's case were Vergil...
And Dante.
Dante grew up as an aggressive and dominant child. He and Vergil had an incredibly violent rivalry, and the blood shed between them could make it rain for days. Vergil preferred graceful battle techniques, mastering the katana and making it an extension of himself, while Dante on the other hand preferred larger, two-handed broadswords and even human weaponry, such as handguns and rifles. The two also could not be more different personality-wise. Though they were identical twins, Vergil's appearance quickly became that of a detached and peaceful warrior who maintained an air of disconnectedness. Dante was the complete opposite, seeking fights and developing a completely random and wild style of fighting which utilized improvisation, and anything in his surroundings. He was loud-mouthed, and it irritated Vergil to no end. When Sparda was sealed away by his own bload seal which kept the Humans and Demons apart, Vergil and Dante battled endlessly over who deserved to inherit his demonic power. Dante didn't care about power so much as merely defeating Vergil, which proved impossible time and time again.
In a sudden turns of events, however, demons attacked Eva when the two were kids, killing her; Vergil vanished that night and Dante was left with nothing. He would spend the next span of years mastering his demonic powers until he meets Enzo, and the two start a shop for hunting demons; Dante seeks Mundus, who killed his mother.
Things went on in this fashion until the reappearance of demons 2000 years after Sparda.
(Devil May Cry 3)
Dante had recently opened the unnamed shop, offering himself for hire as a demon hunter. Business was booming for him when Vergil resurfaced yet again, partnering himself with the mysterious Arkham, who sought to unleash the power of "Temen-ni-gru" upon the world. Temen-ni-gru was the "castle of evil" which housed the portal to the demon world. It was sealed, deep inside, from activation by Sparda's blood oath. Knowing Dante, Vergil had Arkham raise the tower directly in front of Dante's doorstep, ensuring his brother would confront him. Dante didn't care at first, until his store was trashed by monsters. With his shop destroyed, things got personal. Deciding it might be fun to challenge Vergil's house of death, Dante blasts his way through traps, demons of every size, and of course, Jester. Along the way, Dante repeatedly encounters a rather stoic teenage girl. He saves her life at one point, which she responds to by shooting him in the head. He lets her fall, and she survives, but he isn't too pleased with her after.
Dante continues through the castle, uncovering the true purposes of the tower and eagerly challenging anything that moves. After yet another encounter, the teen and Dante reach an understanding between each other, and when the girl says she has no name and says he can call her whatever he wants, he replies with, "Whatever, Lady."
With a hype close to frenzied, Dante obliterates anything that attacks him while going higher and higher, and eventually, comes across "Lady" holding Arkham, who is revealed to be her father. Heartbroken and upset, Lady demands to know if Dante killed her father. Dante knows it must have been Vergil, but says so what if he did. Lady, in her upset, explains that Arkham killed her mother and tried to summon the power of the devil using her as a sacrifice. It failed and Arkham's attained power became unstable and incomplete. A monster. She wanted him to die by her hand for what he did, and claims Dante took that from her. Dante ignores the scene and continues to Vergil, whom he is defeated by yet again. The defeat awakens Dante's Devil Trigger, his innate demonic power-- Dante uses this to chase after Vergil. (But not before being swallowed by a demon whale and then hacking his way through it's body, eventually killing it and leaping from its gut (much to the shock of the nearby Lady.)
After much more fighting and pursuit, everyone winds up in the Seal Chamber, where Vergil realizes that he requires something else to open the portal. Jester shows up and is revealed to be Arkham in a ridiculous disguise, having tricked Lady, Dante, and Vergil into bringing everything he needed to one place. He impales Lady's leg, using her blood as he did with her mother, to finish the ritual and awaken the power of Temen-ni-gru. Dante, along with the others, are scattered to various places in the ruins. At the top of the tower, Arkham chants the prophecy and opens the portal to Hell, taking Sparda's sword and unleashing complete and total chaos. He turns into Sparda, in appearance, and the twin brothers pursue him.
Dante is impeded along the way by Lady, who says she won't let Dante kill her father. Dante battles and effortlessly defeats her, and explains that this isn't a human's job. He tells Lady that her compassion for her family and her behavior has made him feel more motivated to help others, and that he understands "family" a lot better because of her. Dante tells Lady his name, and she tells him to take her valued possession, the Kalina Ann rocket launcher. With it in hand, Dante battles his way through the ruins of the tower, eventually reaching the roof, and flying into Hell. It's unexpectedly peaceful, and Dante is forced to kill the demon soul of each guardian sealed by Sparda. Afterwards, Dante eventually reaches te innermost bowels of Hell and of course meets Arkham, who looks like his father.
Dante watches as Arkham is consumed by the overwhelming power and becomes a mutated, gelatinous blob of evil. Dante and Vergil, for once, team up and mercilessly destroy the monster, chanting their childhood catchphrase; "Jackpot."
After destroying Arkham, Vergil sacrifices himself to keep the seal closed to the Demon World, and disappears. It is implied that he battles Mundus, who defeats Vergil and is the main antagonist of Dante's following adventure.
(Devil May Cry 1)
After Dante and Lady open the Devil May Cry store, the demon hunter is attacked one night by an oddly informed woman named Trish. The woman claims that Mundus, the demon who "killed" Vergil and caused the death of his mother, is gearing up to take control of the Demon World. Dante, seeking revenge, agrees to accompany her to Mallet Island and stop him.
Once there, Dante battles through yet another castle, and discovers that Trish was an agent of Mundus, sent to lead him into a trap and kill him. She was also created by Mundus. Dante also discovers that Vergil was not killed, but brainwashed by Mundus. Dante battles "Nelo Angelo" several time in the story, before it is revealed to be Vergil being controlled.
Dante confronts Mundus and a long battle transcending dimensions ensues, and Mundus kills Trish. Dante cries over her body in despair, screaming that he "wanted to fill her dark soul with LIIIIIIIIGGGGGHHHHHHHTTTTT!!!!1!11!!!111!"
However, she inexplicably comes to Dante's aid to lend him her power, to defeat Mundus, and afterwards, she joins Dante's store (much to Lady's chagrin; the two of them fiercely despise one another in the anime).
(Devil May Cry 4)
Dante is informed by Trish some time later that a cult worshiping Sparda has Vergil's sword Yamato and Sparda's sword, which was given to them by Trish in disguise. Dante seeks the cult out and crashes their sermon, shooting the head priest. He is prepared to search for the weapons when he is suddenly attacked by Nero, a young boy who looks just like Dante for some reason.Nero attacks Dante, believing he is the enemy, and only discovers later that the Sparda cult is entirely evil and intends to revive a god/demon hybrid called the Savior. To this end, Nero is eventually captured along with his maybe girlfriend Kyrie, and the two are used as sacrifices and become a part of the Savior. They fight their way through its insides, while Dante attacks it from without.
Dante, of course, defeats the Savior and rescues Nero from their grasp, before offering to let Nero keep Yamato (which Nero had reforged). Trish keeps Sparda, and in the end, Lady allocates a paycheck to Dante and Trish for their hard work.
Trish complains; Dante doesn't care.
(Devil May Cry 2)
It is implied in the chronological order that DMC2 follows the 4th game, starring Dante yet again being caught up in a struggle to attain the power of demons. A strange girl named Lucia and her mother beg Dante to stop a corporate megalomaniac from attaining godhood using the four Arcana relics. Dante traverses the countryside, fighting all manner of hideous monsters including demon tanks and helicopters. He collects the Arcana and tricks Arius, but in the end, the portal to Arius' goal, the god Argosax, is opened, and Dante has to defeat it, followed by the Embodiment of Despair. After all is said and done, Dante watches the portal to the human world close behind him, leaving him trapped. He revs his motorcycle and drives into the swirling depths of the Underworld once again...