The changing birthplaces of people at the top of Australia's migration tree since 1901 reflect international conflicts, changed political boundaries and the end of racially-biased policies, new Australian Bureau of Statistics data shows.

Stimulated by the gold rushes of the 1800s, Australia's early population was a strange mix with nearly 2000 Australians registered as born at sea by 1891, outnumbering migrants born in Italy and Holland combined at that point.

By the time Federation came in 1901, the population was almost four million and people from Britain and Ireland made up over three-quarters of Australia's overseas-born population. But more migrants were born in Syria than Greece and South Africa combined at that time.

A little over a century later the trend has reversed with 10-times more people born in South Africa living Down Under than have come from Syria.