Dulwich is an area of South London, derives from Dill, a white flower, and Wihs, meaning a damp meadow, giving a meaning of 'the meadow where dill grows'. In 1538, Henry VIII seized control of Dulwich and sold it to goldsmith Thomas Calton for £609. Calton's grandson Sir Francis Calton sold the Manor of Dulwich for £4900 in 1605 to Elizabethan actor and entrepreneur Edward Alleyn. He vested his wealth in a charitable foundation, Alleyn's College of God's Gift, established in 1619. The charity's modern successor, The Dulwich Estate, still owns 1500 acres in the area, including a number of private roads and a tollgate. Alleyn also constructed a school, a chapel and alms houses in Dulwich. Dulwich Almshouse Charity and Christ's Chapel of God's Gift at Dulwich (where Alleyn is buried) still fulfill their original functions.

In the 17th century, King Charles I of England visited Dulwich Woods on a regular basis to hunt.

In 1739, Francis Cox, master of the Green Man, a tavern situated about a mile south of the village of Dulwich, sunk a well for his family. The water was found to be possessed of purgative qualities, and was for some time used medicinally. While the water was popular much custom was drawn to the adjoining tavern, and its proprietor flourished. The oak-lined formal avenue, known as Cox's Walk, leading from the junction of Dulwich Common and Lordship Lane was cut by Cox to connect his establishment of the Green Man Tavern and Dulwich Wells with the even more popular Sydenham Wells.

In 1935, Phyllis Isobella Pearsall, a portrait painter, was on her way to a party. She tried to follow the best available map of the time (a 1919 Ordnance Survey map). She discovered that this map was not up to the task, and ended up getting lost on her way there. Following a conversation during this party, she conceived the idea of mapping London. She claims that the next day, she started mapping London. This involved walking the 3000 miles of the 23 000 streets of London, waking up at 5 am every day, and not going to bed until after an 18-hour working day. (Other sources cast total doubt on this story).

In 1936, when her map was complete, she printed 10 000 copies and began contacting bookstores who might sell it. She tried Hatchards in Piccadilly, Selfridge's, where they would not see her without an appointment, and Foyle's. None of them would take it. Next she went to W H Smith, where they ordered 1250 copies. They sold well and within weeks she was taking orders from every railway station in the south of England. F W Woolworth took a few thousand copies too. By 1938 the London A-Z was well-established.

In 1966, she turned her company, the Geographers' A–Z Map Co, into a trust to ensure that it was never bought out. This secured the future of her company and its employees. Through her donation of her shares to the trust, she was able to enshrine her desired standards and behaviours for the company into its statutes.

A respected typographer, although not credited with the design of any typefaces, her arrangement of type is considered one of the most interesting of her age. The 'A to Z' type-style is a classic piece of typography by Eric Gill.