Theatre: ZENOBIA Young Vic, London

"Death with tits, mate, I'm telling you," is how a Roman soldier sums up Zenobia, the eponymous heroine of Nick Dear's new play. For long stretches of this lengthy work, it's not a description you'd feel much inclined to contradict. A third century AD Syrian warrior queen, she is shown as the spearhead of a bloody rebellion against the Romans (believing them to be responsible for her husband's murder), and as conqueror of the eastern third of the empire.

The play - not so much action-packed as action-congested - might be said to have too many facile ironies in the fire, but the key one is this. When she is defeated by Trevor Cooper's foul-mouthed emperor Aurelian (a crude cavalry man risen from the ranks), Zenobia saves her skin by staging a complete personality rethink.

The patriot who scorned to live "like fleas in the fur of our oppressors" becomes the spoilt wife of a silly Roman senator; the woman who had turned herself into a "vision of unfeminine destruction" dwindles to the role of flirtatious society hostess in her luxury villa in Tivoli. From Queen of the Amazons to Sybil Colefax: Penny Downie's excellent performance demonstrates the ruthless willpower required to make such a transition. "You are such a disappointment," chides Porphyry (Emily Raymond), the girl who escaped to Rome with her, posing as her handmaiden. Dear rubs home the implications of Zenobia's volte-face by contrasting the warrior queen's return to her gender-assigned function with Porphyry's steadfast resolve to devote her life to the unwomanly pursuit of scientific research.

The scale of the piece may be epic, but most of what we see is grim farce and Mike Ockrent's spectacular, populous production relishes the bathetic incongruities that arise. Often you feel that the show can be subtitled "A Jokey, Post-Modernist Thing Happened On The Way to the Forum," or else - given the undignified fate of Robert Gillespie's hapless sycophantic philosopher Longinus who comes to Zenobia's capital hoping for some contemplative peace and quiet and soon finds himself ordered to compose eyewitness verse accounts of her battles - it could be called "From On The Sublime to the Ridiculous." You may end up thinking, though, as the audience rocks with laughter yet again at the idea of grand historical figures using crude modern language ("a fight with a slag in a sandpit") that the play derives its repetitive comedy from fairly cheap sources.

Some key roles are badly under-written, like that of Zabdas (Conrad Asquith), the military commander whose unspoken infatuation with Zenobia turns out, undercuttingly, to be the real cause of all the conflict. True, the play gives a vivid picture of Rome in decline, ever more dependent for the satisfaction of its appetites on the resources of its restive provinces, and there are some fine performances, especially from Clive Rowe's breathy, fat Northern queen of a eunuch, who brings a touch of Coronation Street to these exotic parts. But it tries to cram in so many things (including a coda on the 18th-century discovery and exploitation of the ruins of Zenobia's capital, Palmyra), that it winds up doing justice to none of them.

n Booking: 0171-928 6363 to 21 Sept