Crikey reader Graham Marshall writes:

I put the beginning of the decline of Melbourne and the rise of Sydney at a much earlier time than the eighties. After reading the excellent Tyranny of Distance by Geoffrey Blainey, I believe the decline started with the jet age in the fifties and sixties.

When the only means of getting to the Old World was by ship, the standard route was a kind of curved line that ran from Blighty to Melbourne, via the Southern Ocean. That was the closest to a straight line between the points. Taking that route, Sydney was an extra few days by ship, and until the automobile age it took a similar time overland. Since the first port of call for goods, migrants and visitors was Melbourne, the city inevitably became Australia’s most important.

But since the fifties, the importance of sea travel, particularly for migrants and visitors, declined as jet aircraft became the preferred means of international travel. Sydney is closer to the rest of the world as the crow (or the jet) flies, so it became a more natural choice as first port of call. The first mover advantage in the jet age lifted Sydney above Melbourne.

I’m not a historian, but I believe there is a view out there that the 1956 Melbourne Olympics was the high point of the city, and from that point Sydney started to lift and take over. This concides well with the dawn of the jet age.

One potential hole in my theory is why Sydney flourished rather than Brisbane or Darwin. I would guess that a preferred first port of call must have a critical mass to begin with, an argument that’s supported by the fact that Melbourne was the preferred first port over Perth and Adelaide, even though both are closer to Blighty by ship than Melbourne.