President of the Senate (Australia)
The position is provided for by Section 17 of the Constitution of Australia. The Senate elects one of its members as president at the start of each new term, or whenever the position is vacant. This is usually—though not necessarily—a member of the party or coalition that holds the most seats in the Senate. The largest party in the Senate is not always the governing party, as government is determined by the House of Representatives. The President of the Senate and the Speaker of the House of Representatives may consequently be from different parties.
Father of the Australian Senate
The first Senate was elected on 29 and 30 March 1901. Despite the different election dates, all the members elected to that first Parliament were considered to have had equal seniority. It follows that there could not be a "longest-serving Senator" until only one Senator from the first Parliament was still serving. That occurred on 14 September 1923 with the death of Hon Edward Millen, leaving Sir George Pearce as the sole longest-serving Senator, and thus the first sole Father of the Senate.