It was not until the Scottish Enlightenment, a civilizing time of expansion in the 1700s, that the city fathers decided to break away from the Royal Mile's rocky slope and create a new Edinburgh below the castle. This was to become the New Town, with elegant squares, classical facades, wide streets, and harmonious proportions. Clearly, change had to come. At the dawn of the 18th century Edinburgh's unsanitary conditions—primarily a result of overcrowded living quarters—were becoming notorious. The well-known Scots fiddle tune "The Flooers (flowers) of Edinburgh" was only one of many ironic references to the capital's unpleasant environment, which greatly embarrassed the Scot James Boswell (1740–95), biographer and companion of the English lexicographer Dr. Samuel Johnson (1709–84). In his Journal of a Tour of the Hebrides, Boswell recalled that on retrieving Johnson from his grubby inn in the Canongate, "I could not prevent his being assailed by the evening effluvia of Edinburgh.... Walking the streets at night was pretty perilous and a good deal odoriferous."
To help remedy this sorry state of affairs, in 1767 James Drummond, the city's lord provost (the Scots term for mayor), urged the town council to hold a competition to design a new district for Edinburgh. The winner was an unknown young architect named James Craig (1744–95). His plan called for a grid of three main east–west streets, balanced at either end by two grand squares. These streets survive today, though some of the buildings that line them have been altered by later development. Princes Street is the southernmost, with Queen Street to the north and George Street as the axis, punctuated by St. Andrew and Charlotte squares. A look at the map will reveal a geometric symmetry unusual in Britain. Even the Princes Street Gardens are balanced by the Queen Street Gardens, to the north. Princes Street was conceived as an exclusive residential address, with an open vista facing the castle. It has since been altered by the demands of business and shopping, but the vista remains.
The New Town was expanded several times after Craig's death and now covers an area about three times larger than Craig envisioned. Indeed, some of the most elegant facades came later and can be found by strolling north of the Queen Street Gardens.