Seven

Seven is the most powerful magical number, based on centuries of mythology, science, and mathematics.

Wizarding Community
The Arithmancer Bridget Wenlock, who lived from the year 1202–1285, was the first witch to establish the magical properties of the number seven.

Seven is the age by which most experts believe that magic will reveal itself in a wizard or witch. In the life of the Hogwarts School of Witchcraft and Wizardry community, it is the number of years students must attend Hogwarts before graduating. It is the number of Horcruxes created by Lord Voldemort, specifically because he believed in the numerological power of the number. Harry Potter and Neville Longbottom were born in July, the seventh month of the year; this made them both potential subjects of a prophecy. Arthur and Molly Weasley had seven children; Ginny Weasley is the seventh of them, and the only daughter. There are also seven players on a standard Quidditch team. During the Battle over Little Whinging, six others took Polyjuice Potion in order to take on Harry's appearance as a diversion, thus there were "seven Potters".

Science and Nature
Seven is a common number in science and nature. It is the number of spots on a common ladybug. All mammals' necks have seven bones, with very few exceptions. September was the seventh month of the calendar before July and August were added. There are also seven seas on planet Earth.

There are 7 colors of the rainbow: red, orange, yellow, green, blue, violet, and indigo.

The Native Americans of Montana have seven seasons: chinook season, muddy spring, green summer, gold summer, 'Indian' summer, late fall, and cold winter.

In Korea, in one of the speeches of the reverend Moon, this one declared to have already proceeded to the blessing of 777 couples

There are seven heavenly bodies visible to the naked eye: Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn. In addition, there are seven stars in the star cluster Pleiades (also called the "seven sisters"), one of which Merope Gaunt was named after.

There are 7 saints appearing in the constellation "Saptharishi Mandalam" in Indian Astronomy.

There are traditionally "seven wonders" of the ancient world. There were seven emperors of the classical age of Rome. In the English history period of 500-850 AD, there are seven kingdoms that would eventually become the Kingdom of England in the 10th century: Northumbria, Mercia, East Anglia, Essex, Kent, Sussex, and Wessex.

A common winner combination of most slot machines is 7-7-7.

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Magic and Mysticism
The number seven holds great power in the realms of magic and mysticism. In Judaism, the number seven alludes to the infusion of spirituality and Godliness. For example, traditionally it is held that "God rested on and sanctified the seventh day", or Sabbath. Seven blessings are recited under the chuppah during a Jewish wedding ceremony (Sheva Berachot). Moreover, there are the "Seven Shepherds" who visit the sukkah during the holiday of Sukkot: Abraham, Isaac, Jacob, Joseph, Moses, Aaron, and David. There were seven nations promised to the Israelites when they entered the land of Israel. The menorah holds seven candles.

The "Devil's Number" 6-6-6 is countered by the combination of 7-7-7 which is "God's Number". This number also joins together the principles of the man, 700, the cosmic plans, 70, and their image in the Archetype, 7, according to R. Allendy. It is the universal organization, 7 + 7 + 7 = 21, the general evolution.

Seven further has a presence in mysticism as Yahweh or Jehovah is the divine name in Christianity, whose letters alphabetically equal 70, a product of the divine number 7. There are traditionally seven virtues: Chastity, Moderation, Liberality, Charity, Meekness, Zeal, and Humility. Correspondingly, there are seven deadly sins and seven holy sacraments. According to some traditions, there are seven Archangels.

In Hindu tradition, there are seven worlds in the universe and seven chakras. In Japanese mythology, there are seven Lucky Gods. In the British folk tale Tam Lin, every 7 years the Fairy Queen pays a tithe to Hell. Moreover, in the British tale of of Thomas the Rhymer, he went to live in the faerie kingdom for 7 years. There are seven basic principles of Bushido.

There were also seven main islands constituting the mythological land of Atlantis.

In Septimus Heap, a seventh son for a seventh son is very Magykal (Magyk is the like magic in Harry Potter).

Behind the scenes

 * Dursley has seven letters.
 * Their are seven puzzles leading up to the Philosopher's Stone:
 * 1) Hagrid's pet, Fluffy
 * 2) Sprout's Devil's Snare
 * 3) Flitwick's flying keys
 * 4) McGonagall's giant chess set
 * 5) Quirrell's troll
 * 6) Snape's potions
 * 7) The Mirror of Erised


 * The First-Years enter the castle in the seventh chapter of the first book.
 * Many fans expected Harry Potter and the Deathly Hallows (the seventh book) to be released on 07/07/2007, which also happened to be a Saturday, the day upon which Harry Potter books had previously been released. However, it was released on July 21st of that year instead, two weeks later. It is thought that the more 'magical' date was rejected due to it also being the 2nd anniversary of the 7/7 London Bombings in 2005.
 * In the Wizarding world, wizards and witches come of age at the age of seventeen, instead of eightteen.
 * The number on the back of Harry Potter's Quidditch robes in the Prisoner of Azkaban movie is seven.
 * Out of the nine members of the Order of the Phoenix in the Advance Guard Harry hadn't already been acquainted with seven of them beforehand.
 * The mother of Blaise Zabini had been married seven times as of 1996.
 * There are also seven conflicts in Harry Potter and the Deathly Hallows:
 * 1) The Battle over Little Whinging
 * 2) Infiltration of the Ministry of Magic
 * 3) The Attack at Godric's Hollow (1997)
 * 4) Ambush at the Lovegood House
 * 5) The Battle of Malfoy Manor
 * 6) 1998 Break-In of Gringotts Wizarding Bank and
 * 7) The Battle of Hogwarts


 * Chapter four of Harry Potter and the Deathly Hallows is entitled "The Seven Potters".
 * J. K. Rowling stated in interview that she chose to write seven books in total because she spent seven years in secondary school. Also, she wanted Harry to come of age at seventeen because it "just seems a good number for a wizard to come of age."
 * Harry Potter defied death from the hands of Lord Voldemort seven times:
 * 1) In Godric's Hollow in 1981
 * 2) Over the Philosopher's Stone while Voldemort was in control of Quirinus Quirrell
 * 3) In the Chamber of Secrets in 1993
 * 4) In Little Hangleton in 1995
 * 5) During the Battle of the Department of Mysteries
 * 6) During the Battle over Little Whinging
 * 7) During the Battle of Hogwarts


 * Molly and Arthur Weasley have had seven children.
 * In 1996, while brewing the Draught of Living Death in a Potions class, Harry followed the alternate instructions in the Half-Blood Prince's copy of Advanced Potion-Making, by stirring his potion once clockwise after every seventh stir counter-clockwise. This helped him achieve much better results than the standard instructions, and earn Slughorn's praise.
 * The epilogue is seven pages in total.
 * Seven people escape from Malfoy Manor:
 * 1) Mr. Ollivander
 * 2) Luna Lovegood
 * 3) Dean Thomas
 * 4) Dobby
 * 5) Harry Potter
 * 6) Hermione Granger
 * 7) Ronald Weasley


 * There are seven hundred fouls in Quidditch.
 * The Marauder's Map shows seven secret passages out of the school.
 * School at Hogwarts goes for seven years.