BECAUSE IT'S on HBO and can show sex, violence and assorted cruelties, the new pay-cable series "Rome" wastes no time doing all three.

But because the historically based miniseries uses the triad to paint a portrait of a Roman republic in decline, where morality has more to do with power and alliances than right and wrong, it all becomes part of a fascinating look at the events beginning in 52 B.C.

The series, with new episodes airing Sunday nights at 9 on HBO, runs into early November.

With a multinational cast, sets that capture the rich details of the Roman world and stories that intertwine historical events with trysts and plots aplenty, the joint production of HBO and the BBC is rich, powerful and habit-forming television.

Make no mistake, this isn't a kind and gentle miniseries, just as the struggle between Julius Caesar and the Romans who plotted against him wasn't kind and gentle.

In the Rome to which Julius Caesar eventually turned his troops after conquering Gaul, sex was a commodity and a means to power.

Plots and schemes played out both in the Roman Senate and in the richly appointed suites of men who formed alliances and women who used everything from weddings to beddings to gain an advantage in this culture based on power and personal loyalty.

The story begins just as Caesar and his friend and ally in Rome, Pompey Magnus, are dancing around the concept of finding themselves on different sides of the struggle for power in these waning days of the Roman republic.

Ciaran Hinds makes Caesar a tough, interesting leader, tired from years of the campaign against Gaul and ready to bring his troops back to Rome to take on an aristocracy that's gotten fat and powerful. The reforms he's ready to bring to the city aren't at all well received.

Kenneth Cranham is just as interesting as Pompey, who tries to minimize the fallout from strategically opposing his old friend, but slowly realizes that war will come.