The Advertiser was founded in 1858. Between 1893 and 1929,Sir John Langdon Bonython was its sole proprietor. He also held the post of editor for 45 years, and under his direction the Advertiser became a prominent Australian daily newspaper. It appealed to the growing middle class and was proudly South Australian, although Bonython was determined that its coverage should be as complete as possible. The newspaper prospered, partly thanks to the prominence given to small advertisements.
Bonython had been an advocate for Federation, and promoted the cause through his newspaper. Indeed, he represented South Australia in the Federal Parliament for several years from 1901 as a Protectionist. Bonython was also a noted philanthropist, giving significant sums of money to educational institutions, and to the needy during hard times. He also gave a large sum of money towards the completion of Parliament House in Adelaide.