And in the middle of all this is the love story between the Pharoah's son Amenophis and Moses' niece Anai.
Gioacchino Rossini (1792-1868) actually wrote two operas on the same subject: "Mose in Egitto" for the Teatro di San Carlo in Naples in 1818, which he then substantially revised, expanded and renamed "Moise et Pharaon" for the Paris opera nine years later.
This second version proved such a runaway box-office success that it was performed no less than 100 times between its premiere in 1827 and 1838.
Nowadays, however, it is barely performed at all, eclipsed by Rossini's lighter works such as "The Barber of Seville", "The Thieving Magpie" or "La Cenerentola".
Italian maestro Riccardo Muti conducted a highly successful staging of "Moise et Pharaon" in La Scala in Milan in 2003 and so was the obvious choice for Salzburg's new production.
And Muti insists that the second version of "Moses" is the better opera.
"I prefer it because Rossini himself preferred it," he told journalists at a news conference here last week.
"Don't get me wrong. 'Mose in Egitto' is a wonderful opera, but it remains very much a mere sketch for 'Moise et Pharaon'. And it's not just me who says that, but the great Rossini himself."
At a time when even the glitzy Salzburg Festival is compelled to cut costs, finding a director for the project proved more difficult, said Salzburg chief Juergen Flimm.
"Our first choice was an Italian director, but that didn't work out. The costs spiralled out of control. So we agreed to go our separate ways and it sort of landed on my desk," Flimm said.
Flimm reportedly took over the direction of "Moise" for the symbolic fee of just one euro.
However the German director admitted that he felt no artistic necessity or urgency to stage "Moise et Pharaon" at all. And that, unfortuantely, comes across loud and clear in his slapdash directing of Rossini's monumental epic.
The sets, by Austrian designer Ferdinand Woegerbauer, are undeniably handsome: a towering curved wall of untreated wood acts both as the arid Mount Sinai and the enclosed space where the Israelites are held as slaves.
But chorus and soloists alike mill around aimlessly, sit or kneel, with seemingly no clear direction or dramatic intent.
It would be difficult to depict the plagues of frogs and locusts suffered by the Egyptians credibly and effectively on stage. Even so, Flimm's solution of simply projecting the pertinent passages from the Old Testament onto the curtain is a bit of a cop-out.
Flimm said he had made a conscious decision not to glibly update the action to modern times.
"We haven't transposed it to the Gaza Strip, there are no tanks," he said.
But he nearly manages to skirt the issue of the persecution of the Jews, except for the last act, where they set off to cross the Red Sea carrying shabby suitcases, as if about to be shipped off to the Nazi death camps.
The paucity of Flimm's ideas was most noticeable in the love story between Anai and Amenophis, where black screens simply dropped down allowing the singers to come forward to the front of the stage and sing their arias directly to the audience.
On the musical side, Maestro Muti more than made up for Flimm's vacuous staging.
The Vienna Philharmonic was in dazzling form, and the excellent Vienna State Opera Chorus was perhaps the real star of the show.
Among the soloists, there were no big names, but upcoming US tenor Eric Cutler stood out as Amenophis.
Latvian soprano Marina Rebeka enraptured the Salzburg audience in her big aria "Quelle horrible destinee" in the final act, but best of all was the supple, velvety bass of Russian Ildar Abdrazakov as Moses.
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