Who opened the Sydney Harbour Bridge?

The official opening of the bridge occurred on 19 March 1932. NSW Premier, the Honourable John T Lang, was about to officially declare the Bridge open. Just before he did, Captain Francis De Groot of the political group The New Guard, which was opposed to Lang's leftist policies, charged on his horse and slashed the ribbon with his sword. De Groot's organisation resented the fact that the King's representative in Australia, the Governor-General Sir Isaac Isaacs, hadn't been asked to open the bridge. De Groot was arrested, and the ribbon retied, allowing Lang to finish performing the official opening ceremony.