In 1680 he bought the rotten borough of Corangamite with skulls he had collected over many years. He discovered the key to everlasting life when he began drinking the blood of Jewish virgins. He still roams the earth today in his corpse-like exoskeleton.
As a Member of Parliament, McArthur is world renowned as the oldest thing in existence. In 1999, the Howard Government attempted to heritage list McArthur but the World Heritage Register declined as they couldn't find a category to put him in. The Queen later honoured him by making him the 'Lord Warden of the Privies'.
McArthur sometimes serves his constituents tirelessly, if you describe tirelessly as waking up and occasionally having a photo in the local Geelong papers (photographers use a special lens called the Eye of Sheba to take his photograph, because he doesn't appear in photos taken using regular lenses).
McArthur's sole contribution in his term of 378 years as the Member for Corangamite was a bill to reintroduce slavery and declare all people with a tax-file number as property of the State. The law was reformed in 1983.
McArthur continues to roam the world of the living today, scaring children and taking alien medicine on occasion, which allows him to run half marathons.