From Irish Pedigrees; or the Origin and Stem of the Irish Nation by John O'Hart
Arms: Gyronny of eight sa. and or. on the first four acorns, and on the last as many oak leaves counterchanged. Crest: A lamb reguard. holding over the dexter shoulder a flag, charged with an imperial crown. 
EINSIODA, brother of Maolclochach who is No. 101 on the "MacNamara" pedigree, was the ancestor of O'h-Iocaigh, and MacIocaigh anglicised Hickey, and Hickie.
101. Einsioda: son of Cuilean.
102. Ainiochadagh: his son.
103. Iocaigh ("ioc:" Irish, a payment): his son; a quo O'h-Iocaigh and MacIocaigh.
104. Michliagh: his son.
105. Erc: his son.
106. Donall O'Hickey: his son; first assumed this sirname.
107. Deaghadh: his son.
108. Aedh: his son.
109. Cormac: his son.
110. James: his son.
111. Cormac (2): his son.
112. Teige: his son.
113. Owen: his son.
114. Muireadhagh: his son.
115. John: his son.
116. Aedh (or Hugh): his son.
117. John (2): his son.
118. John (3) O'Hickey: his son.
The O'Hickeys were formerly Chiefs of a district in the vicinity of Killaloe, County Clare, also of a cantred in the barony of Upper Connello, in the County of Limerick. They were hereditary physicians to the O'Briens, Kings of Thomond; to the MacNanamaras, lords of Hy-Caisin; and to the O'Kennedys of Ormond; and several of them are said to have compiled and translated valuable medical works, amongst others Nichol O'Hickey, the translator into Irish of a Latin Medical Work, called "The Rose," known also as the "Book of the O'Boulgers." The O'Hickies possessed a copy of "The Lily," a celebrated Medical Work, compiled in A.D. 1304, of which several transcripts are known to exist.
1. James Hickie, Esq., of County Clare, whose estates were seized on by the English in 1652.
2. William; his son.
3. William (2): his son.
4. Michael: his son.
5. William (3): his son.
6. William (4): his son.
7. William Creagh Hickey, Esq., J.P.: his son; the representative of this family, living at Killelton, County Kerry, in 1864.
 Hickey: Rev. William Hickey ("Martin Doyle"), well known for his efforts to elevate the condition of the peasantry of Ireland, was eldest son of Rev. Ambrose Hickey, rector of Murragh, co. Cork. He was born about 1787, graduated at St. John's College, Cambridge, and subsequently took the degree of M.A. in the University of Dublin. He was ordained a clergyman of the Established Church in 1811, and appointed to the curacy of Dunleckny, co. Carlow. In 1820 he was inducted into the rectory of Bannow, co. Wexford , in 1826 was transferred to that of Kilcormick, in 1831 to Wexford, and in 1834 to Mulrankin, where he ministered the remainder of his life. As a parochial clergyman he was esteemed alike by Catholics and Protestants. He commenced his career as a writer in 1817, his first work being a pamphlet on the State of the Poor in Ireland. Afterwards followed a series of letters under the pseudonym of "Martin Doyle," under which he continued to write. He wrote numerous works; his latest production, published a few years before his death, was Notes and Gleanings of the County Wexford. In all his writings he took the broadest philanthropic views, studiously avoiding religious and political controversy. He was awarded a gold medal by the Royal Dublin Society, in recognition of his services to Ireland, and enjoyed a pension from the Literary Fund. He was a man of an eminently charitable and feeling nature, and died comparatively poor, 24th October, 1875, aged 87.