Love

"There is a room in the Department of Mysteries that is kept locked at all times. It contains a force that is at once more wonderful and more terrible than death, than human intelligence, than the forces of nature. It is also, perhaps, the most mysterious of the many subjects for study that reside there. It is the power held within that room that you possess in such quantities and which Voldemort has not at all."

- Albus Dumbledore to Harry Potter about love

Love is a deep, powerful, and ineffable emotion of attachment to, and affection for, another person or people. It gives those who experience it the ability to do very great things. Someone full of hate, such as Tom Riddle who has never known it even once in his entire life, cannot understand love's full magical properties.

This magic is also common in Muggle books and reality.

Love is a form of magic that is surprisingly difficult to comprehend.

1890s
In 1899, Albus Dumbledore's love for his brother and sister pushed him to turn against his old friend Gellert Grindelwald and attack him, finally defeating him in 1945.

1920s
In 1925, Merope Gaunt had fallen deeply in love with Tom Riddle, and betrayed her family's beliefs in blood purity to be with her love. She used a Love Potion in order to attract Riddle to her, but ceased feeding him it once she was pregnant, thinking that Tom would finally love her in return, or at least stay for their unborn child out of love for it, of which Tom did neither. The usage of a love potion for Tom Riddle Jr.'s conception is what led him to unable to understand love for his entire life, as it was due to coercion rather than true love.

1970s
In 1977, James Potter's love for Lily Evans changed his character a little, by the fact that he stopped hexing people just for the fun of it.

1980s
"The Boy Who Lived. How lies have fed your legend Harry. Shall I reveal what really happened that night thirteen years ago? Shall I divulge how I truly lost my powers? Yes, shall I? It was love. You see, when dear sweet Lily Potter gave her life for her only son...she provided the ultimate protection. I could not touch him. It was old magic. Something I should have foreseen. But no matter, no matter. Things have changed. I can touch you...now!"

- Voldemort reflecting on his first defeat

In 1981, Severus Snape's love of Lily Evans pushed him to join the Order of the Phoenix, even though he hated her husband. In that same year, Lily's love for her son Harry protected him against Lord Voldemort. He became the only known person in history to survive the Killing Curse because of the power of her loving sacrifice.

After Barty Crouch Jr. was imprisoned in Azkaban, his mother persuaded his father to help break him out. Crouch Sr. agreed out of love for his wife, even though he did not love his son at the very least.

1990s
In 1992, Because of the protection that Lily Evans's death created for Harry Potter, Professor Quirinus Quirrell could not touch Harry with out serious harm to his physical well being. In doing so, this lead to Professor Quirinus Quirrell's death and Voldemort was once again without a body to possess. .

In 1993, the love for his sister, Ginny, and Hermione Granger caused Ron Weasley to head down to the Chamber of Secrets to rescue her.

In 1994, the love for his godfather and the prospect of living with him gave Harry a powerful and happy enough memory to perform a Patronus Charm and drive away the Dementors.

In 1995, Harry managed to escape Lord Voldemort when his loved ones came to him through Priori Incantatem.

In 1996, his love for Sirius again helped him, when his grief over his godfather's death pushed Voldemort out of his mind. In that same year, Dumbledore ignored Harry, thinking that this would prevent Voldemort from using the connection with Harry Potter to gain insight into his own mind, because Voldemort would sense he cared "too much" about Harry and would be eager to use their relationship to gain access to Dumbledore's mind and knowledge of the activities of the Order of the Phoenix.

In 1997, Harry Potter's love for Ginny Weasley was shown when he entered into the common room after the Quidditch match that took place during his detention with Professor Snape and ended up kissing her, and it also drove him to leave her in fear of her being a target of Lord Voldemort. In that same year, Harry's love for Professor Albus Dumbledore pushed him to attack Severus Snape with one of his own spells. Draco Malfoy's love for his family pushed him to attempt to kill Dumbledore, even though he really did not want to. Fleur Delacour asserted her love for Bill Weasley even after he was horribly scarred in battle by Fenrir Greyback. Her declarations prompted Tonks to once again impress upon Remus Lupin she did not care about his being a full werewolf, older than her, or that he was poor, that she loved and wanted to be with him anyway.

Their love for Harry motivated Hermione Granger and Ron Weasley to accompany him on the Horcrux hunt, leaving their families and risking their lives.

"...Do not pity the dead, Harry. Pity the living, and, above all, those who live without love."

- Albus Dumbledore

During the Battle of Hogwarts, Lucius and Narcissa Malfoy's love for their son motivated them to look for him instead of fighting. In the end, Harry's love finally destroyed Lord Voldemort once and for all. Harry's love for people caused him to offer Voldemort a chance of redemption.

Love in literature
"Now you are healed and will know true love!"

- The maiden


 * Amata fell in love with a muggle named Sir Luckless.
 * Cadmus Peverell was so in love with his dead lover, that he killed himself so he could finally join her.
 * The Warlock in The Warlock's Hairy Heart regarded love as a sickness, therefore he paid dearly for it.

Love and magic
Love has a profound effect on magic. Lily Evan's love for her son made her willing to die for him, and because of that sacrifice, Harry was protected from the most powerful Dark magic of all — the Killing Curse. Love is the only protection against the lure and power of the Dark Arts, which are fueled by hateful emotions. Harry failed to learn Occlumency in order to block his connection to Lord Voldemort's mind, but he managed to block the link when he focused on his feelings for his loved ones, such as when he felt grief over his godfather's death and when he was frantic with worry about Hermione Granger when she was being tortured by Bellatrix Lestrange.

"Hermione was screaming again: The sound went through Harry like physical pain. Barely conscious of the fierce prickling of his scar, he too started to run around the cellar, feeling the walls for he hardly knew what, knowing in his heart that it was useless.... He felt Voldemort’s fury, but as Hermione screamed again he shut it out, returning to the cellar and the horror of his own present."

- Harry Potter cutting off his connection to Voldemort

Love can also affect other types of magic, notably the Patronus. Harry's Patronus is the same as the Patronus and Animagus form of his father, a stag. James' wife had a doe Patronus to match her husband's, and Severus Snape's mimicked her's because of his love for her. Nymphadora Tonks's Patronus changed to a werewolf when she fell in love with Remus Lupin.

Love Potions, like Amortentia, and Entrancing Enchantments, are meant to artificially create love, but they cannot; nothing can reproduce love. Instead, they can at most produce an intense infatuation. When a person smells Amortentia, they will smell things that remind them of what and who they love. Within the love room of the Department of Mysteries is where love is being studied, and a large fountain of Amortentia is kept.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Goblet of Fire (film)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Deathly Hallows
 * Harry Potter and the Deathly Hallows: Part I
 * Harry Potter and the Deathly Hallows: Part II