Vegemite was developed by food technologist Cyril P. Callister for the Australian company Fred Walker & Co. in 1922 and, after a public competition to create a name, was first sold in 1923. Its competition was the imported Marmite, and initial sales were slow. Promotion of the health benefits of Vitamin B saw sales grow in the 1930s and the “Happy Little Vegemites” song in the 1950s cemented the brand as an Australian icon.
The current owners of the Vegemite brand are Mondelez International. They appear to have a certain paranoia about other people linking to their website and say it’s “strictly prohibited”. However, if you do a Google search for Vegemite and go to their site you’ll find a great timeline in the Heritage section. Or you can use this url: http://www.vegemite.com.au/Pages/heritage-vegemite-timeline-1920.aspx