Lucius Malfoy

"I assure you, my Lord, I have never renounced the old ways. The face I have been obliged to present since your... absence...that is my true mask."

- Lucius to Lord Voldemort in Harry Potter and the Goblet of Fire.

Lucius Malfoy is the tertiary, later true main antagonist of Harry Potter and The Chamber of Secrets and a recurring villain from the Harry Potter franchise. He is a former Death Eater, the son of Abraxas Malfoy, the husband of Narcissa Malfoy, the brother-in-law of Bellatrix Lestrange, the father of Draco Malfoy, the father-in-law of Astoria Malfoy, and the grandfather of Scorpius Malfoy. He is a rival of the good-natured Arthur Weasley, patriarch of the poor Weasley family.

In the films, Malfoy is portrayed by Jason Isaacs, who was also the voice of Ra's Al Ghul in Batman: Under the Red Hood, Satan in Castlevania: Lords of Shadow, Colonel William Tavington in The Patriot, Admiral Zhao in Avatar: The Last Airbender, The Grand Inquisitor in Star Wars: Rebels, and Captain Hook in the 2003 Peter Pan film.

Past
Lucius was born in 1954 and in 1965, at the age of 11, attended his first year at Hogwarts School of Witchcraft and Wizardry, sorted (like the majority of his family who went there) into the Slytherin house. He was also a member of Potions teacher Horace Slughorn's "Slug Club". He was also a close friend of Severus Snape and eventually graduated from Hogwarts in 1972. Later on during the First Wizarding War, he married Narcissa Black and became a Death Eater, a follower of the Hogwarts prefect-turned Dark Wizard Tom Marvolo Riddle/Lord Voldemort. Later on after the war and the defeat of the Death Eaters, he joined with the Ministry of Magic and became a quick rival of Arthur Weasley. However, he had sought to bring Voldemort back to power.

Chamber of Secrets
Lucius first appeared in Chamber of Secrets, where he is introduced in a book shop in Diagon Alley. While mocking the Weasleys, he slipped Tom Riddle's Diary into the belongings of Ginny Weasley in the hopes that Voldemort would come back to power by draining Ginny's life force and taking back his rightful place as leader of the Death Eaters. This, in turn, leads to the petrification of multiple students at the school by "seeing" the Basilisk that the diary's hidden sentient memory had command over.

Lucius' own plan was to use Ginny's "trance" given by the diary's power to open the Chamber of Secrets and get the headmaster Albus Dumbledore kicked out of the school by the Ministry's command, since the Chamber's opening and the presence of the Basilisk and petrifications would make it clear that Dumbledore was incompetent. In the end, after the Basilisk is killed by Harry, the diary's magic power is destroyed by Harry using a Basilisk tooth and (with Ginny, Ron Weasley and the amnesic Gilderoy Lockhart) escaping from the Chamber with Fawkes the Phoenix, Lucius came to Dumbledore and brought his House Elf Dobby with him, revealing that the Malfoy family are the masters of Dobby. Harry had discovered that Lucius had slipped the diary into Ginny's cauldron back in Diagon Alley, but gets the response "Why don't you...prove it?". He had no proof to this, but through the loophole that Dobby can be freed if his master is given clothes and the fact that he had given Dobby the useless diary while Harry's own sock was in its pages, Dobby had been freed. Lucius, furious at Harry, tried to murder him right there on the spot only to be shot at by Dobby's own magic. He promises Harry that he will meet his parents in hell and leaves angrily, ready to plot a way to get back at Harry. After this he was stripped from the Hogwarts School of Governors.

Prisoner of Azkaban
He is unseen in the third installment, but he has a plot influence. Here, after Draco is attacked by gamekeeper of Hogwarts Rubeus Hagrid's hippogriff Buckbeak, Lucius found that this animal is easy to angry. Despite that Draco had been insulting Buckbeak and was attacked for it, Lucius convinced the Ministry of Magic to execute Buckbeak at sundown so he doesn't endanger anyone else. However, through the use of a Time Turner (a time-traveling device), Harry and Hermione Granger save Buckbeak from the execution party.

Goblet of Fire
Lucius appears at the beginning of Goblet of Fire when he attends the Quidditch World Cup with Draco and Narcissa. He seemed disgusted that Arthur and his family got to be at the top of the stadium to watch due to their poorness and is angry even more so when he finds out that Harry is accompanying them to the Cup. Later when the game was over, he had got some Death Eater friends together and tortured the Muggle site manager of the World Cup stadium. He even rubbed their faces to the Weasley's that they sit in the worse seats ever, he and Draco sit in the Ministry's box.When the Death Eaters attacked the stadium's surrounding campsite and left the "Dark Mark" in the sky, Lucius was already gone. Near the end, when Voldemort was resurrected, we see that the Dark Lord was angry at his minions for failing to find him during the World Cup campsite attack. It reveals that the fathers of Draco's friends Vincent Crabbe and Gregory Goyle were Death Eaters, and even Lucius was a Death Eater. After Voldemort's battle with Harry, Lucius went away back to the Ministry and try to convince the Ministry that Harry's claims about the Return of the Dark Lord were ludicrous.

Order of the Phoenix
Malfoy was rather pleased to see that Voldemort had returned to full health. Lucius is seen in Order of the Phoenix as one of the Death Eaters who were sent to retrieve a special prophecy that was about Voldemort and Harry Potter. He leads the group that consists of himself, Bellatrix Lestrange, Antonin Dolohov and a few other unnamed Death Eaters. After unsuccessfully retrieving the prophecy and the fact that prophecies can only be used by those actually IN them, it meant that he couldn't use it. He is seen fighting members of the Order of the Phoenix in the Battle of the Department of Mysteries and is stunned by Sirius Black, who is killed moments later by Bellatrix. He is sent to Azkaban at the aftermath of the battle.

Deathly Hallows
He escapes from Azkaban in Harry Potter and the Deathly Hallows in which he lends his house, Malfoy Manor to the Dark Lord as his headquarters and is regarded as a disgraced Death Eater. At the Skirmish at Malfoy Manor, Hary, Ron and Hermione were captured by Bellatrix and taken to Malfoy Manor, but they escape and battle the Death Eaters. Dobby, looking to repay Harry for freeing him from the Malfoy's control 5 years ago, Apparates the heroes and the captured Luna Lovegood away, but not before getting wounded by Bellatrix's knife throw, which does end up killing him.

When Voldemort and the Death-Eaters came to Hogwarts for the final battle, Lucius came along too along with his wife. Because Lucius' wife, Narcissa, lied to Lord Voldemort about Harry Potter being dead and it helped Harry to defeat him, the Malfoy family could use this to get a pardon.

Trivia

 * Lucius is the true main antagonist of Chamber of Secrets because he initiated the plot by smuggling Tom Riddle's Diary into Hogwarts, causing the events of the film to unfold. Therefore, Dobby had told Harry that it was "a plot to make most terrible things happen."
 * Lucius is rather racist (much like Cornelius Fudge) in that he treats half-bloods like scum, often calling them "Mudbloods".