Born in Belfast and now aged 55, McKillen built his reputation on hard work, long hours and a tough negotiating stance.
He first sprang to prominence thanks to his role in developing the Jervis Street Shopping Centre off O’Connell Street, Dublin, in the late ’80s.
His start in business took place after his move to Dublin, when he began work with the family business, DC Exhausts, rising to the position of managing director.
By 1989 he had been appointed to the Construction Industry Development Board by then Environment Minister Padraig Flynn, before embarking on a number of projects with Johnny Ronan, including the Temple Bar Hotel.
Over the years he has dipped into and out of various businesses, and by the middle of the last decade he part-owned a number of franchises across Dublin, from Tower Records to Captain America’s.
His property interests take in locations in the North, France and in Japan and Vietnam, as well as London.
It was there, in 2003, that he paid €38m for an investment site on Oxford Street, and a year later he was part of the consortium that bought the Royal Opera House portfolio in Covent Garden.
Clarendon Properties, in which McKillen had a stake, bought other properties, including the Savoy Shopping Centre in Cork. McKillen is a co-owner of the Maybourne Hotel Group, the company behind the five-star Connaught, Claridge’s and Berkeley hotels in London, and it is his interests here that are central in his court case against NAMA.
Notoriously media-shy, he is friends with a number of people in the celebrity firmament, including designer John Rocha, who he paid €125,000 for a jewel-encrusted cow created for an exhibition in 2003, with the money going to the Simon Community, one of a number of charities McKillen’s donates to.
His legal team includes Nobel Prize-winning economist Joseph Stiglitz among them, showing NAMA will be facing a tough competitor in the courts.