Of the former outworks of the fortress little trace remains. On the east of the tower, at about a hundred yards distant, is what an old inhabitant stated to be a disused channel of the River Manghane or Brinny. This fact is borne out, and contradicted, respectively by several maps. The fact that the field lying west of the river is still called “Castle Garden” seems to point out that the channel of the Brinny has been changed. Also the north and west walls of the fortress have the greater number of crenellated openings, which show that they were considered the most vulnerable sides.
The Down Survey map of 1656 shows a dwelling-house to the east of the castle.
In the mortar on the inside surface of the arch, the marks of the twigs are still visible which formed part of the temporary support used when building. The mortar has much less lime than is usual in such work, no doubt from the distance it would have had to be brought.
These markings, as well as the general architecture, indicate that the date 1476, which is usually stated as the time of its erection, is likely to be accurate.
It is supposed to have been built by Barry Oge, or Barry the Younger, whose family displaced the O’Mahons in this district, being a descendant of Philip de Barry, the Anglo-Norman invader.
The lands of Innishannon were granted to the Barry Oge family either in Henry III.’s or Henry IV.’s reign.
In 1449 Barry Oge forfeited the confidence of the Crown, and his lands were seized for the King. But a letter of the time states that he was there “upon the King’s portion, paying his Grace never a penny of rent.” At this time wars at home and abroad had weakened the English power in Ireland, and it is most likely that Barry Oge built Dundaniel Castle to protect the lands he was holding in spite of the forfeiture.
In 1548 mention is made of a pirate called Colle coming to Kinsale in a pinnace and marrying Barry Oge’s aunt, living in his castle, and not allowing any one to enter Kinsale. Probably this castle was Dundaniel, where the honeymoon was being spent, but the Barry Oge himself does not seem to have shared the odium in which his uncle-in-law was held.
Pirates were a very grave trouble to the south coast for many years following.
After the Desmond rebellion Barry Oge’s land was again forfeited in 1588, and bestowed upon MacCarthy Reagh, and in 1599 “Downdandier” is referred to as being in his possession.