Donal III O'Donovan (Irish: Domhnall Ó Donnabháin), The O'Donovan of Clancahill, born before 1584, was the son of Helena de Barry[1] and Donal II O'Donovan, The O'Donovan of Clancahill. From the inauguration of his father in 1584 to the date of his own accession to the chiefship in 1639, the O'Donovan family had risen to become one of the most prominent Gaelic families remaining in all the province of South Munster or Desmond, from a position of semi-obscurity in the mid-16th century, although this was in part due to the misfortunes and sad decline of several once more prominent families, as happens in all ages. Donal II had also been an aggressive seizer of lands during and especially following the Nine Years' War and his son's inheritance, thought to have been approaching 100,000 acres (or possibly greater considering all septs and territories under his control), was colossal for a Gaelic family of the time. His father also living to a great age, Donal III is believed to have been in his late 50s or early 60s when he began his career as Lord of Clancahill. He died in 1660 at the age of 80 or greater.