A well-known businessman and solicitor from Milford left more than €15m in his will.
According to documents lodged with the Probate Office, James Osborne left a total of €15,286,826.
The popular solicitor and businessman died in Donegal in August at the age of 68.
According to the Sunday Independent, he was a well-known figure in corporate Ireland who held a variety of senior boardroom positions.
A former managing partner of legal firm A& L Goodbody, he was one of the most sought-after non-executive directors in Ireland.
He was a former chairman of Independent News and Media, publishers of the Sunday Independent, and was a director of Ryanair.
Mr Osborne was born in Devon but his roots were in the town of Milford, Donegal His father was a commander in the Royal Navy, which brought the family to Plymouth and later to postings further afield.
His family returned to Milford, where his great-grandfather was a doctor and where his grandfather, John Allen Osborne, later founded the family legal practice.
Mr Osborne followed his grandfather into the legal profession, studying at Trinity College and later joining A & L Goodbody.
He became managing partner and helped build the firm into one of the country’s biggest practices. He worked closely with some of Ireland’s most successful business people, including Dermot Desmond and Larry Goodman.
He retired from Goodbody at the age of 45 but kept an office there and continued to work as a business consultant, joining the boards of Bank of Ireland and Golden Vale.
Mr Osborne was a long-standing director of Ryanair and a close adviser to its chief executive, Michael O’Leary.
