One would usually be safe to assume that a Test series is usually supposed to include no more than five Tests and even if one is talking about the Ashes, it would be a safe assumption. However, that is not the case and had it not been for Australia's crazy decision to have seven Tests in their summer during the 1970-71 Ashes, then it would never have been possible.
The marathon ended in ignominy for the hosts as England won the Ashes 2-0 and the captain Bill Lawry was sacked in the middle of the series. That being said, Australia did gain by promoting the young Ian Chappell to the top job and he was responsible for bringing about another great era in the country's cricketing history.
The third Test of the series at Melbourne saw another historic event when on the 5th day the two teams played in the first ever one day international after the game had been washed out by rain. Australia won the game by 5 wickets, just like they had won their first ever Test match all those years ago.