Ever the entrepreneur, Ryan was an art collector, owned a stud ranch in Kentucky, a vineyard in Bordeaux, and in 2005 donated 10 million euros to found a new business school in Dublin. Although he referred to himself as "just a Tipperary farmer" he spent most of his time in Monte Carlo for tax reasons. He is survived by his wife Mairead and their three sons.
At the age of seventeen, Keating joined the First Kerry Brigade of the Irish Republican Army in 1920. He took part in two major 1921 attacks on British auxiliaries (Black and Tans) at Castlemaine and Castleisland where up to twelve Black and Tans were killed. The ambush also resulted in the deaths of at least five police officers and five IRA members.
In Ireland's Civil War (1922-3) Keating fought against former colleagues as a member of the IRA faction that opposed the 1921 peace treaty with Britain. He was eventually captured by the Irish Free State forces and spent seven months in a prisoner of war camp.
He served several short terms in prison for insurrectionary activity, including an aborted assassination attempt of a former general of Free State forces. Keating took part in an IRA bombing campaign against London in 1939-40.
Dan Keating was a staunch believer that Ireland could not be at peace until the border dividing the Republic of Ireland from the North was eliminated. He maintained his position of hard-line Republicanism until the end. As a member of the Provisional IRA, Keating spent 27 years trying to overthrow British rule.
Even after the Provisional IRA's 1997 cease-fire agreement and decision to support Sinn Fin to push for a negotiated deal, Keating switched allegiance to a breakaway faction that supported continued bombings. Denouncing the past 15 years of peacemaking efforts as "a joke," Keating made one of his last appearances in a 2007 newspaper ad appealing to Sinn Fin not to begin cooperating with the police in Northern Ireland.