GUINNESS or MacGUINNESS
Lords of Iveagh, County Down
From Irish Pedigrees; or the Origin and Stem of the Irish Nation by John O'Hart
The ancient Arms of this family were: Vert a lion ramp. or, on a chief ar, a dexter hand erect, couped at the wrist gu. 
Cionog (or Cionga), brother of Ros who is No. 63 on the "Line of Ir," p. 301, was the ancestor of MacAonghuis [oneesh]; anglicised MacGuinness, Maginnis, Magennis, Magenis, MacInnes, Guinness, Angus, Ennis, Innis, etc.
63. Cionga: son of Rory Mór.
64. Capa (or Cathbharr): his son.
65. Fachna Fathach: his son; the 92nd Monarch of Ireland.
66. Cas: his son; and brother of Conor MacNessa, who deposed Fergus MacRoy from the sovereignty of Ulster.
67. Amergin: his son.
68. Conall Cearnach: his son; the famous warrior, so often mentioned in the Irish Annals as connected with the Red Branch Knights of Ulster.
69. Irial Glunmhar: his son; King of Ulster; had a brother named Laoiseach Lannmor, who was also called Lysach, and who was the ancestor of O'Moore.
70. Fiacha Fionn Amhnais: Irial's son; who, of the line of Ir, was the 24th King of Ulster, in Emania.
71. Muredach Fionn: his son; King of Ulster.
72. Fionnchadh: his son.
73. Connchadh (or Donnchadh): his son.
74. Gialchad: his son.
75. Cathbha: his son.
76. Rochradh: his son.
77. Mal: his son; the 107th Monarch.
78. Firb: his son.
79. Breasal Breac: his son.
80. Tiobrad Tireach: his son; was the 30th King of Ulster, of the Irian line; and contemporary with Conn of the Hundred Battles, the 110th Monarch of Ireland, whom he assassinated A.D. 157.
81. Fergus Gaileoin (or Foghlas): his son.
82. Aongus Gabhneach: his son; a quo O'Gaibhnaigh, anglicised Gowan, MacGowan, O'Gowan, Gibney, Smythe, Smith, etc.
83.Fiacha Araidhe: his son; from whom, who was the 37th King of Ulster of the Irian line, the ancient territory of "Dalaradia" (sometimes called "Ulidia," comprising the present county of Down and part of the county Antrim) was so named.
84. Cas: his son; had a brother named Sodhan; who was ancestor of O'Manning, MacWard, etc.
85. Fedhlim: his son; King of Ulster.
86. Iomchadh: his son.
87. Ros: his son; King of Ulster.
88. Lughdheach: his son.
89. Eathach Cobha: his son; from whom Iveagh, a territory in the county of Down, derived its name; and from that territory his descendants in after ages took their title as "Lords of Iveagh."
90. Crunnbhadroi: his son.
91. Caolbha: his son; the (123rd and) last Monarch of the Irian race, and 47th King of Ulster.
92. Conall: his son; had three brothers: 1. Feargan, who was the ancestor of MacCartan; 2. Saraan, who was the last King of Ulster, of the Irian race, and in whose time the Three Collas conquered Ulster; 3. Conla.
93. Fothach: son of Conall.
94. Main: his son.
95. Saraan: his son.
96. Mongan: his son.
97. Aodhan: his son; had a brother Foghartach, who was ancestor of MacArtan.
98. Feargus: son of Aodhan.
99. Breasal Beldearg: his son.
100. Conchobhar: his son.
101. Domhnall: his son.
102. Blathmac: his son.
103. Laidhne: his son.
104. Aidiotha: his son.
105. Aongus ("aon:" Irish, excellent; "gus," strength): his son; a quo MacAonghuis. This Aongus was called Æneas Mór.
106. Aongus Oge (or Aodh): his son; first of the family who assumed this sirname.
107. Eachmilidh: his son.
108. Aongus: his son.
109. Eachmilidh: his son.
110. Flaitheartach: his son.
111. Aodh (or Hugh) Reamhar: his son.
112. Dubhinsi: his son.
113. Giolla Coluim: his son.
114. Ruadhrigh: his son.
115. Eachmilidh: his son.
116. Murtogh Riaganach: his son.
117. Art (or Arthur) na-Madh-mainn: his son.
118. Aodh (or Hugh): his son.
119. Art: his son.
120. Hugh: his son.
121. Conall Mór: his son; had two elder brothers—1. Hugh, 2. Eachmilidh (who had a son Hugh), and seven younger brothers—1. Felim, 2. Edmond, 3. Cu-Uladh, 4. Muirceartach, 5. Brian, 6. Ruadh-righ (Rory, or Roger), 7. Glaisne.
122. Donall Oge: son of Donall Mór.
123. Hugh (also called Feardorach or Ferdinand): his son.
124. Art Ruadh [roe], or Sir Arthur Magennis, of Rathfriland: his son; was in 1623 created Viscount Iveagh, county Down; m. Sarah, dau. of Hugh O'Neill, Earl of Tyrone, and had issue—1. Hugh Oge, of Iveagh, who had a son named Arthur; 2. Conn, 3. Arthur, 4. Rory, 5. Daniel (who is No. 125, infra); 6. Rose, 7. Evelin, 8. Eliza. He was buried in Dromballybrony on the 15th June, 1629.
125. Daniel: son of Art Ruadh; m. Eliza Magennis; d. 1658.
126. Bernard, a Colonel: his son; d. 1692. Had a brother Roger Mór, who m. N. Cavanagh.
127. Roger Oge: son of the aforesaid Roger Mór; m. Maria Magennis. Had a brother Bernard, who was a Lieutenant-Colonel, 1703-1734.
128. Heber: son of Roger Oge; d. 1760.
129. Arthur: his son; a Captain; d. 1794. (See the "De la Ponce MSS.")
 Guinness: Sir Benjamin Lee Guinness, Bart., a distinguished member of this family, born 1st November, 1798, was an opulent brewer, in Dublin, and M.P. for Dublin from 1865 until his death. He is best remembered as the restorer of St. Patrick's Cathedral, Dublin, at a cost which has been estimated at £130,000; and as the head of a business firm that has acquired a world-wide reputation. He died possessed of a large fortune, and, besides several mansions in and near Dublin, was the owner of a beautiful estate at Cong, in the county of Mayo, on the shores of Lough Corrib. He evinced great and practical interest in Irish archaeology by his tasteful preservation of the antiquarian remains upon his large estates. He died on the 10th May, 1868, aged 69, and was buried at Mount Jerome, Dublin.—Webb.
 MacGowan: The Arms are: Ar. a lion ramp. gu. between two cinque foils vert. Crest: A talbot pass.
 Sodhan; According to the Linea Antiqua this Sodhan was the ancestor of O'Dugan.
 Bernard: This Bernard had a son Roderic, who in 1707 was Page de . . . . and d. 1726.
 Colonel: This Lieutenant-Colonel Bernard Maginnis had a son Murtagh, who was a Captain, and who had a son Charles-Francis, b. 1745.