The feast day to Mary Help of Christians has been celebrated in Australia since 1844 but the history to this day dates back to the start of the 1800's.
Napoleon Bonaparte had jailed Pius VI who died in jail. When Pope Pius VII was elected he too was jailed by Bonaparte, who kept him prisoner at Fontainbleau. The Holy Father vowed to God that if he were restored to the Roman See, he would institute a special feast in honour of Mary. Twelve months later the Pope decreed that the feast of Mary Help of Christians be kept on 24 May. She is the patroness of Australia.