Why was Canberra built from nothing in 1913?

Because Sydney and Melbourne would not let each other have it. When the Australian colonies federated in 1901 the rivalry was sharp enough that the constitution simply specified a new capital, in New South Wales but at least 100 miles from Sydney, with Melbourne serving in the interim. It took until 1927 for parliament to actually move.

The design came from an international competition won by Walter Burley Griffin and Marion Mahony Griffin, American architects who had worked with Frank Lloyd Wright - and Marion's drawings, rendered on satin, are widely credited with winning it. The plan works with the landscape rather than over it, with axes aligned on surrounding hills and a lake at the centre. It was then obstructed, altered and underfunded for years, and Griffin resigned in frustration in 1920.

The result is a city that has never quite escaped being an argument's outcome. It is orderly, green and much mocked by Australians as a place where nothing happens, and the word Canberra is used in Australian journalism the way Westminster or Washington is - to mean the government rather than the town, which is precisely what it was built to be.