"Henry VIII was red-haired and fat; there's no doubt about that, " said Trinity College historian Professor Ciaran Brady. "There are enough portraits of him around that point to prove that. He certainly didn't have black hair and he got fat pretty early on in his life as well."

While it's quite clear to everyone that Rhys Meyers is far too good-looking to portray the bloated King Henry, the characters in The Tudors also speak in an entirely different way to the 16th century English people they portray.

"It's fair enough, because you'd never hold the audience's attention if the characters spoke like they did during that time, " said Brady.

"But it is a problem with historical novels and films. When you translate into modern language, you inevitably change the thoughts and feelings of the people at that time.

And in that sense, you can fail to capture the real mood of the times like, for instance, Thomas Wyatt's poetry manages to do."

Although Henry is only 25 when the series starts, most of the events that take place in the series actually happened when he was in his mid-to-late 30s. Catherine of Aragon, played by a tightlipped Maria Doyle Kennedy, was only six years older than Henry, rather than the 15 years as portrayed in the series. And Henry's illegitimate son, the duke of Richmond, did not die in his infancy, but lived until he was 17.

The sexual tension and numerous liaisons around court, however, are exactly indicative of the times.

"The royal court in Henry's time had an incredibly tense and aggressive atmosphere and there was a real intensity there that comes across rather well in The Tudors, " said Brady. "It was a very erotically-charged place."

One of the most bizarre storylines in The Tudors is that of Henry's only sister, Margaret, who is made to marry an ancient Portuguese king and ends up smothering him to death in their marital bed.

In fact, Henry VIII had two sisters, Mary and Margaret.

Margaret married James IV of Scotland, while Mary married Louis VII of France after lengthy diplomatic negotiations.

"It's really odd that they would have made it the king of Portugal, as this marriage was quite an important event in history, " Brady said. "Portugal didn't play a role in British diplomatic relations at all at the time. King Louis was very old and died fairly soon after their marriage, so that's obviously what they're basing it on. They just don't seem to have bothered to be accurate and in other storylines they seem to have taken gossip as fact. . .But I suppose one can be too snooty about these things."