Ángel, parte I

Angel (born 1727 in Galway, Ireland) is a fictional character created by Joss Whedon and David Greenwalt for the television programs, Buffy the Vampire Slayer and Angel. The character is portrayed by David Boreanaz.

Character history
Angel was born as Liam, to an Irish merchant, in 1727. By 1753, at the age of 26, he had developed a taste for alcohol, women and sloth. Though not a bad man, Liam was a hedonist whose only real ambition lay in seeing the world. For the lazy Irishman, that seemed a laughable dream, especially after he was expelled from his father's household, but he had caught the eye of an affluent woman — actually a vampire — named Darla. She lured him into an alley, and, promising him a world full of excitement and travel, transformed him into a vampire.

Angelus during the 18th cenutry.
The loss of his soul meant Liam no longer possessed any restraint over his darker impulses. On the night he rose from his grave, and in response to Darla's claim that he could have anyone in the village, he set about slaughtering the entire community. When he came to slaughter his own family, he found no problem in entering, his little sister inviting him in without hesitation or suspicion. Before killing his father, he would tell him mockingly, "[My sister] thought that I'd returned to her. An angel. She was wrong." For generations Darla and Liam, now known as Angelus, terrorized humankind, murdering and torturing anyone who crossed their path. Angelus sired the vampires Penn (who indulged his blood lust by becoming a serial killer), and Drusilla, a young woman driven insane by Angelus before he finally sired her. Drusilla, in turn, sired Spike, for whom Angelus largely served as a mentor and "role model." Spike would go so far as to call the elder vampire his "Yoda".
According to Angel in the episode "City of", he had been around for 14 wars. And "Vietnam doesn't count; they never declared it."

Re-ensoulment
In 1898, Angelus slew the favorite daughter of a tribe of Gypsies, the Kalderash Clan. To avenge her death, they cursed him by restoring his human soul, thus afflicting him with a conscience and condemning him to an eternity of remorse. He tried and failed to resume his life with Darla. After he was unable to kill a baby during the Boxer Rebellion to prove himself to Darla, Angelus fled (presumably to the United States). There he lived an isolated life avoiding humanity, and the temptation to feed, living in a dark apartment.
Angel arrived in New York via Ellis Island 1902 (Angel Season 4 Episode 15 Orpheus)
During WWII, Angel was recruited by The Demon Research Initiative who sunk him to the bottom of the ocean to rescue an American submarine crew from Nazi captured vampires (including Spike). The American crew had stolen the German submarine. Angel sired Lawson here.
In 1952, Los Angeles, Angel was a resident at the Hyperion Hotel, the building which would one day become the future base of Angel Investigations. During this time, Angel was attempting to stay to himself, avoiding interaction with other patrons and looking the other way when his help was required, even despite the numerous strange incidents of murders and suicides running rampant throughout the hotel. After his meeting with a young woman named Judy, he was forced to disarm a man chasing her but then immediately ended any interaction with her soon after. However her repeated attempts to contact him managed to help him build a, luke-warm at best, relationship with her while the hotel continued to become corrupted around him. Though he didn't understand why, Angel felt compelled to help the human residents of the hotel by defeating the Paranoia demon affecting them, but by the time he had obtained the items he required, the entire hotel had been overcome with paranoia and not only did Judy betray him in order to save herself, but the hotel residents beat and then hanged him. This was a turning point in Angel's life where he got close to a human and tried to selflessly help her and the other residents, but in the end decided it was not worth saving them, bitter at their actions against him. He returns many decades later to find Judy an old woman, having been trapped in the Hyperion all this time feeling guilt at Angel's apparent death by hanging because of her accusations. Angel forgives her and remembers her fondly as one of his first few friends.
In New York during the 1970s, Angel came upon a robbery at a doughnut shop. After the robber killed the employee and fled, Angel stayed with the man as he died. Unable to resist the urge to feed from a warm human, Angel fed on the man and then grew disgusted with himself. He exiled himself to a life of homelessness, living in alleyways and feeding off of stray rats. A shadow of his former self, a reclusive and emotionally tortured Angel eventually met a demon named Whistler in 1996, who persuaded him to join the fight against the evil that had corrupted him and to help the newly called Vampire Slayer, Buffy Summers. When he and Buffy finally meet in Sunnydale, CA, he introduces himself not as Angelus, but as Angel.

Angel's doomed romance with Buffy is a centerpiece of the show.
Angel's story before he met Buffy unfolds in flashbacks scattered among numerous episodes of both "Buffy the Vampire Slayer" and "Angel". They were not presented in chronological order. A guide to finding the flashback or flashbacks to a particular event is at Angel, Darla, Spike and Dru: Before 1997.
Over time, Buffy and Angel fall in love. Though they try to deny their feelings, they cannot resist the passion growing between them. When they finally consummate their relationship, Angel experiences the one moment of pure happiness needed to break his curse. Without the humanity and conscience that was instilled by his soul, Angel quickly returns to his former, evil self.
After Angel transforms back into Angelus, he allies himself again with Spike and Drusilla, who had recently settled in Sunnydale. Angelus finds immense pleasure in tormenting Buffy and her friends. He goes on to kill Jenny Calendar, who had been a core member of Buffy's group, just after she manages to successfully decipher the lost Gypsy curse which would restore Angelus' soul. He then attempts to awaken the demon Acathla in an attempt to bring about the apocalypse. Buffy, however, is determined to stop him despite their deeply emotional history. Fighting him in one-on-one combat, Buffy is able to overcome Angelus, but before Acathla consumes him, Angel is cursed again by Buffy's friend and comrade Willow Rosenberg, his soul restored moments before Buffy has to kill him and, in doing so, save the world.