Jeremy Irons tells Helen Barlow about his portrayal of a philandering pontiff in raunchy TV series The Borgias.

IN Leonardo da Vinci’s Lady with an Ermine, a young woman holds a long, skinny animal in her arms. An ermine is a stoat in its white winter coat. Irish stoats don’t turn white but mainland European ones do.

THEY’VE plotted and deceived, they’ve been warlike, corrupt and power-hungry and they’ve sired children they shamelessly promoted: the history of popes, as cardinals mull who will succeed John Paul II, is decidedly murky.