Owning a castle in idyllic countryside may seem like a fairy-tale of old to many but, for father and son the Earl of Erne and Viscount Crichton, it's a very modern story of struggling finances and family responsibility.

Their family home of Crom Castle has been the ancestral seat of the Crichton's for more than 400 years. And as the only boy in a family of five children, John (Viscount Crichton) will one day inherit the castle from his father, Lord Erne.

Keeping The Castle, on BBC One NI on Monday, January 28 at 10.35pm, tells the story of a father and son who are determined to maintain their family home and heritage in increasingly difficult times.

Crom Castle, which was used as the location for the current BBC series Blandings, was once one of grandest privately owned castles in Ireland, playing host to lords, ladies and royalty. Indeed the family has its own royal connections as Lord Erne's father was equerry to King George VI. King George VI was also Lord Erne's godfather and, at the age of 15, Lord Erne was a page at the Queen's Coronation.

Born in 1937, Lord Erne inherited Crom Castle when he was just two-years-old after his father was killed in the Second World War. He moved to Crom when he turned 21.

Lord Erne said: "I came here to live in 1958 when I came of age to find a castle completely empty with no electricity or any central heating and rather modest acres. I mean I spent a lifetime looking after this place and I love it like�I can't describe how much I love it." Lord Erne and his wife brought their five children up in the castle but as the financial pressures of running the estate mounted over the years, in 1987 they gave much of their land and historic outbuildings to the National Trust and Crom Estate was opened to the public.

While the castle remains privately owned, the running of it has continued to be a costly concern and, in recent years, Lord Erne has moved to the south-side wing of the building while his son John has taken over the west wing.

John, who lives in a two-bed apartment in London and runs a successful property business there, has been tasked with finding ways to bring money into the castle in order to help the family keep their home.

He has made the west wing available for commercial ventures, such as weddings and, more recently, as the location for the BBC comedy drama Blandings. And while business has certainly been coming in to Crom Castle, John must also achieve the difficult balance, not only between his life in London and his life in Crom, but also between commercialism and privacy - as the castle remains the home of his parents.