In 11th century France Godfrey of Ibelin (Liam Neeson, barely disguising his Ballymena drawl), a knight who has found a profitable existence in Jerusalem, returns from the Holy Lands to meet his son Balian (Orlando Bloom), a blacksmith who is mourning his wife and child, and asks him to join him in the Crusades.

Initially reluctant, circumstances eventually drive Balian out of his home and on the long journey by land and sea to a new life in politically instable Jerusalem. He is soon made a knight and finds that his humble roots provide him with both enhanced diplomatic and development skills, but also greater vulnerabilities as the city is gradually torn apart by power struggles and religious divides.

If all this middle age epic journeying and adventure stuff this sounds slightly familiar then you'd be right in thinking there is more than a passing resemblance to Lord of the Rings (indeed one can only imagine how much cash Kingdom of Heaven could have saved itself if they'd reused some of LOTR's set and costume cast offs) as well as containing a lot of the stirring earnest men of honour vs. men of breeding stuff from Scott's lauded epic Gladiator.

However, there are important differences here. Scott has learned a few things from both his filmmaking rivals and the special effects challenges of Gladiator - for instance here we will get fogs and colours subtly altered by computer but we are far more likely to be seeing volumes of real human extras (mostly Moroccan army men given the king's permission to work on the film) than get badly pixilated digital crowds.

From the volume of fight scenes and the shooting style he's adopted for the major action (choppy slow mo' in particular) it would seem he's also been taking a look at Crouching Tiger, Hidden Dragon and House of Flying Daggers. It may all sound a little derivative, but Ridley Scott has crafted something extremely vibrant, convincing and enjoyable. Indeed, although it was something of a box office flop when it was originally released (in a substantially cut and inaccurately marketed version) Kingdom of Heaven proves to be really exceptionally good.

The performances are universally good, but it is particularly gratifying to see Orlando Bloom living up to all that leading man promise. He is charismatic, intelligent, and brings us a Balian with an understandable absence of faith and a sense of honour, if not always kindness. Perhaps the only implausible thing is that Balian seems to always be in the middle of all the action and yet is left unscathed. He has a sort of unbreakable Teflon quality but thankfully Bloom's square-jawed leading man qualities are about enough to let you overlook some of the less historically accurate background details and unlikely multitasking.

Jeremy Irons' Tiberias is a treat to watch. His friendship to the dying King Baldwin (an uncredited and almost unrecognisable Ed Norton) and uneasy relationship with Martin Csokas's gloriously vile Guy de Lusignan and the Knights Templar place him firmly in allegiance with Balian of Ibelin. Together with Balian's faithful friend and servant Hospitaler, played with a wonderful sense of from ever reliable David Thewlis, they are the moderate voices among a court anxious to provoke war with Saladin and his substantial army.

Meanwhile, a Falstaff-ish Reynald (Brendan Gleeson giving a furiously debauched performance) eggs Guy on as Guy's wife Sibella flirts with Balian and sympathises with his views. Sibella is a character, we are told, virtually removed from the cinematic release so it is a shame that so much of Eva Green's restored performance involves her looking glamorous in a terribly Turkish Delight ad circa 1984 way and yet offering so little guide to her actions. Her son, briefly ruler after Baldwin's death, is also featured but the romanticism of both his and Baldwin's infirm innocence and savant musings can be a little too clawing in insisting that, like Balian's family, all the truly good die young but there is hope for the rest of us if we can only learn by their example. The heavy handed symbolism is unfortunate and the frisson between Sibella and Balian unnecessary in a largely mature and interesting film.

Talking of symbolism it is certainly not hard to see parallels between the Crusades as depicted here and the current political climate and that is clearly an intentional comment from Scott on the attitude of the West in its interventions in Middle Eastern life. It is therefore refreshing that this epic battle of religions and ideologies shows the Muslim characters, and particularly the "Saracon" leader Saladin (Ghassan Massoud), in an unusually reasonable and sympathetic light.

The film makes it clear at all times that characters of all faiths are equally passionate, noble and flawed individuals (some reasoned, some men of violence and action alone) whose actions have complex motivations and consequences. Of course whether a 14-year-old watching this at the cinema will truly catch that between testosterone-fuelled violence may be debatable but at least that violence looks gruesome and very much a futile and rather inhuman way in which to settle difference.

So what's the verdict? Well Kingdom of Heaven is gloriously shot, brilliantly acted and very well, if historically inaccurately, scripted. Having black screened musical overtures and other such pretentious details actually proove to be a benefit as they let you become fully immersed in this very different time and place.

For almost 4 hours of movie the pacing is surprisingly nippy and the gloriously textured soundscape never does anything other than compliment or enhance the action on screen. There is something a little self-indulgent about leaving so many tangential plots in here and there are places where, frankly, history is far more interesting than the too convenient plot changes.

However, this film has enough going for it that most of these niggles are room for improvement rather than out and out problems. Kingdom of Heaven is an extremely entertaining and very accessible mix of action adventure, romance and anti-war sentiments with a welcome touch of theology on a truly epic scale.