With a cornucopia of sex, politics and religious conflict, the life of Henry VIII seems well suited to dramatization on screen. After all, even in the rollicking 16th century, it is impossible to find another king who had six wives, executed nobles and prelates at a whim and provoked the Vatican into ordering his excommunication.

Yet if high drama seems assured, casting the right actor to play the lead is trickier because, unlike the case with most English monarchs before Queen Victoria, we know exactly what Henry Tudor looked like. And he was no matinee idol. As seen in Hans Holbein’s famous portraits, he was square-headed, bearded and seriously overweight.

In other words, he did not look at all like Jonathan Rhys-Meyers, the handsome 29-year-old Irish actor who is playing Henry in “The Tudors,” Showtime’s 10-part series, currently being filmed in and around here [Dublin] and scheduled to be broadcast in the United States early next year.