It was a sight only fantasists would have believed possible six months ago: Hosni Mubarak, the man who ruled Egypt for three decades with an iron fist, wheeled into a Cairo courtroom on a hospital gurney and locked in an iron cage.
Mr Mubarak is the first Arab leader overthrown by his own people to face justice – an undeniably momentous event not just for Egypt but for the whole of the Middle East. The trial was not orchestrated by the West (as in Iraq) and the ex-president was actually in the dock (in contrast to Tunisia, the first domino of the Arab Spring). But we must not be dazzled by the drama and the symbolism of this opening day, for it will be the manner in which the whole trial unfolds that will prove the real barometer of the new Egypt.
Scepticism about whether Mr Mubarak will be held to account is justified. The judges got their jobs during the defendant's reign, as did the prosecutor. The generals now running the country also owe their careers to him.
Putting Mr Mubarak on trial is one of the few demands that unite the disparate strands of the protest movement that toppled him in February. It is to be hoped that yesterday was not simply a staged humiliation to appease the angry youths, who have been out in force again in Tahrir Square – until the Egyptian army moved in to clear them earlier this week, using tactics ripped from the Mubarak security handbook.
Egypt's interim rulers have a real opportunity to break the cycle of impunity for the powerful and oppression for the dissenting. The military council must keep its promise to organise credible democratic elections this year and then return to barracks, relinquishing all levers of power, while Mr Mubarak's trial must set high new standards of accountability for the pharaohs who follow him.