(Tony Bourke worked on the racing desk at The Age for 42 years, the majority as chief racing writer.)

If everything goes to plan, the upcoming Royal Ascot meeting could mark the beginning of a defining period for Australian racehorses on the international scene and could realistically mean we have the two most highly-ranked horses in the world by the end of the year.

Champion mare Black Caviar already shares that honour with English colt, Frankel, who runs in the St James Palace Stakes (1600m) on Tuesday, while dual Cox Plate winner So You Think is long odds-on to further enhance his already-exploding international reputation in Wednesday's Prince Of Wales Stakes (2000m).

The campaign set for So You Think is still flexible but, if things go as planned, he will be contesting either the Prix de l'Arc de Triomphe (2400m) at Longchamp or the Breeders' Cup Turf in the US in October.

The now Aidan O'Brien-trained So You Think has already won rave notices after his two warm-up runs in Ireland, but he will meet his first serious rival in the French galloper, Planteur, in the Prince Of Wales Stakes.

Although Black Caviar is currently resting on her laurels, her presence hovers over the Royal Ascot meeting in the shape of Star Witness and Hinchinbrooke who have been left in her wake every time they have met but are expected to be major players in the two feature sprints this week.

Star Witness is the ruling favourite for the Group 1 King's Stand Stakes (run overnight Tuesday) while Hinchinbrooke, better known as a stablemate of Black Caviar, runs in Saturday's Golden Jubilee Stakes.

Any discussion in England about the two Australian representatives invariably gets back to Black Caviar and a media conference last Thursday at Newmarket, where they are being prepared, was highlighted by the news that, all being well, Black Caviar will be here next year.

Danny O'Brien, trainer of Star Witness, makes no secret that he is more than happy with not having to contend with Black Caviar.

''It's been a long term plan to bring Star Witness (for the King's Stand) because he is such a good straight track horse and it's a got to be a bonus if you don't have to run into Black Caviar," O'Brien said.

Trainer Peter Moody, who arrived at Newmarket, last Thursday to supervise Hinchinbrooke's final gallops, has confirmed that Black Caviar will be travelling overseas in the next 12 months but they have not worked out specific targets.

''Everything is on the table and that includes where she might be going in the spring,'' he said.

Moody was very impressed with the way Hinchinbrooke galloped on the Poly track at Newmarket on Saturday and is confident the four-year-old will not let the side down in the Golden Jubilee.

Moody and stable jockey Luke Nolen will be among the strong Australian contingent at what will be the 300th Ascot, although the Royal Patronage began 268 years ago, a staggering figure when you consider Australia was discovered by an Englishman almost three decades after that, in 1770.

Unseasonable rain in recent days in London has raised a small query about how the track will play this week but, by Australian standards, it should be around a dead rating on Tuesday.