Donal II's inauguration in 1584 by his father-in-law Owen MacCarthy Reagh is testified to in a complicated lawsuit filed essentially against the both of them by O'Donovan's younger brother Teige sometime previous to 12 February 1592.

Loftus decided in Donal II O'Donovan and MacCarthy Reagh's favour, declaring them legitimate and rightful, with Teige getting nothing, however it is possible there were related events back in Carbery because Owen was deposed by his nephew later that year.

First of all, it substantiates the report made a century later by Sir Richard Cox, 1st Baronet in 1690 that the O'Donovans were considered one of the four families in Carbery of royal extraction,[8] because the White Rod or slat, mentioned in the case as received by O'Donovan from MacCarthy Reagh, was for a king or Rí of some grade in origin, in this case a subordinate lord princeps (prince) or petty king, in the Irish understanding, receiving his rod from his superior or overking.

Curiously, in spite of Crown policy, which forbid the use of Gaelic titles, Loftus refers to Donel O'Donevane as simply O'Donovan (meaning the head of his sept and thus Lord of Clancahill, etc.

"[13] Besides the case of his accession above, O'Donovan is first noted in 1586 for burning to the ground the newly built house of the Protestant Bishop of Cork, Cloyne and Ross, William Lyon.

He destroyed the glass windows of the church, took the lead off, pulled down the Queen's arms then standing over the gate of my house and trod them under-foot.Although not among the major figures of his time, Donal II was in their company and active in Munster affairs during the Nine Years' War, being one of the few southern lords to support Hugh O'Neill.

[18] In March 1599 pledges of loyalty to the English Crown were received from all the lords in Carbery except for O'Donovan and some MacCarthys, and because of this Sir Thomas Norris "... caused their castles and houses to be taken and razed, and their people and lands to be spoiled", as he wrote to the Privy Council.

[21][22] The letter was intercepted, and for his part and signature Donal's people were "pacified" savagely by the English forces under the command of Captain George Flower, who related:[18] From Ross we marched over the Leape, into O Donovan's country, where we burned all those parts, and had the killing of many of their churls and poor people, leaving not thereon one grain of corn within ten miles of our way, wherever we marched, and took a prey of 500 cows which I took to be drowned and killed, for that we could not trouble ourselves to drive them in that journey.The plan was that O'Donovan and Florence's brother, Dermod Maol MacCarthy, would invade a number of territories to the north of Carbery,[21] but this was obviously unrealized.

I believe this is true.But this was only true in the sense that they were not all present at the final Battle of Kinsale itself in late December/early January, almost a month after Castlehaven, although apparently O'Donovan made an appearance (on the Irish side) earlier during the siege.

[26] Changing allegiance after this ruinous event, O'Donovan joined Owen's sons Finghin and Donogh Maol, and O'Driscoll, in siding with the English, and O'Sullivan Beare wasted the territory of Clancahill after hearing of it.

After the war O'Donovan fared particularly well and ended up in control of at least a few more territories than he began with, the result a combination of the government granting him lands (or rents) seized from septs of the MacCarthys and others, and his own aggressive efforts.

Following this the descendants of Teige, a son of Donal II with Johanna MacCarthy Reagh, inherited the style of O'Donovan and built their own stately house, known as Lissard, to replace the centrality of Bawnlahan.

Belonging to Donal's household was the blind harper Conchubhar Mac Conghalaigh,[36] for whom the lament Torchoir ceól Cloinne Cathoil was composed by the bardic poet Tadhg Olltach Ó an Cháinte.

[37] Both Donal and the Lady Joanna are mentioned in the poem, where her grief for the harper is described (12th stanza): Cumhthach ar aoi a daltáin daillinghean Eóghuin mheic Dhomhnuill,is baoth mar oire a hosna,saoth lem chroidhe an Charrthachsa.Sorrowful for her blind darlingis the daughter of Eóghan son of Domhnall;her sigh is senseless as a burden;this lady of Clann Charrthaigh is distress to my heart.Also mentioned is Dáire Cerbba, 4th century progenitor of the Uí Fidgenti and Uí Liatháin.