"Some people argue that the oldest pub in London is the White Hart on Drury Lane; others that it is the Angel on Bermondsey Wall, or the Lamb and Flag on Rose Street. All of these people are Muggles, and all of them are wrong. The oldest pub in London, as any wizard will tell you, is the Leaky Cauldron on Charing Cross Road."
The Leaky Cauldron was built in the 1500s by Daisy Dodderidge. The Leaky Cauldron was there long before Charing Cross Road was even planned; its true address is number one Diagon Alley, and it is believed to have been built along with the rest of the wizarding street. Created some two centuries before the imposition of the International Statute of Secrecy, the Leaky Cauldron was initially visible to Muggle eyes. While the pub was, from the first, a place for witches and wizards to congregate — whether Londoners or out-of-towners up for the day to shop for the latest magical ingredients or devices — Muggles were not turned away or made to feel unwelcome, even though some of the conversations, not to mention pets, caused many an unwary drinker to leave without finishing his or her mead.
In 1692 with the imposition of the International Statute of Wizarding Secrecy, Minister Ulick Gamp permitted the pub to continue its existence as a safe haven and refuge for members of the magical community. Though insistent on numerous concealment spells and good behaviour from all who used the pub, Gamp was sympathetic to the need of wizards to let off steam during this difficult time, and further agreed to give the landlord permission to let people into Diagon Alley from his backyard, because the shops behind the Leaky Cauldron were now also in need of protection. Out of gratitude, the landlord created a new brand of beer, Gamp's Old Gregarious, which tasted so disgusting that even with a one-hundred-Galleon incentive, nobody could finish a pint.