Britain's Queen Elizabeth and the Duke of Edinburgh have left Australia to return to Britain.

The queen ended her tour of Australia Saturday at a barbecue in the western city of Perth. Authorities say tens of thousands of people lined the banks of the Swan River to catch a glimpse of the royal couple.

The 85-year-old monarch had been in Perth to open the Commonwealth Heads of Government Meeting at the end of a national visit, which included Canberra, Brisbane and Melbourne.

Her visit was capped by a historic agreement by the Commonwealth member nations who agreed to repeal a centuries-old rule that favors sons over daughters to take the royal throne, even if the daughter is the first born.

The agreement was reached Friday on the sidelines of the 54-nation meeting that brings together all nations once linked to the former British empire.

The leaders of 16 nations that have Queen Elizabeth as their monarch also agreed to scrap the rule that bans the heir to the throne from marrying a Roman Catholic.

The changes were offered by British Prime Minister David Cameron, who called the rules outdated and senseless.

The rules have been under scrutiny since the marriage earlier this year of Prince William, second-in-line to the British throne, to Kate Middleton.

The three-day Commonwealth meeting opened Friday amid concerns about the group's relevance in the 21st century. Queen Elizabeth told the leaders in her opening remarks the meeting “promises to bring new vibrancy” to the grouping.