The marathons were motorsport rallies which were run between 1953 and 2008. They circumnavigated Australia, or at least, a vast part of the continent.

The early years were tremendously popular as the roads linking large portions of the country were in poor condition. Automobile manufacturers enthused over events that provided a particularly severe test for their products, proving their cars were able to stand up to whatever conditions remote Australia could provide.

Early editions of the event were heroic tests and were front-page fodder for the newspapers of the era. 

In all, there have been 15 Marathon Trials although only eight made the full journey to be called Round Australia Trails – the 1954 and 1955 Redex Trials, the 1956, 1957 and 1958 Mobilgas Trials, the 1979 Repco Trial, 1995 Mobil Trial and 1998 PlayStation Rally.

Tom Snooks was a key part of the Organisation for a number of these Marathon events.