Melbourne has overtaken Sydney as Australia’s largest city due to a technicality.

Sydney’s population overtook Melbourne’s in 1902 and for more than 100 years that’s how it’s remained — but Melbourne has now reclaimed that title.

Press PLAY below to hear what’s changed to give Melbourne the title

The change means means the city’s ‘Significant Urban Area’ is home to about 4.8 million people, eclipsing Sydney by 18,700.

Demographer with id consulting, Glenn Capuano, says it’s “in a little way unfair to Sydney, because Sydney has the central coast, which is part of their greater capital city area but it’s not in the significant urban area and it never can be because there’s a little thing called the Hawkesbury River that sits in the way of it ever being continuous with Sydney”.