Siobhán O'Donnell

Siobhán was the daughter of Hugh McManus O'Donnell, Lord of Tyrconnell.^[3] Her mother was Sir Hugh's first wife^[1][4][5] (not his second wife, Iníon Dubh).^[4][5][1] Historian Francis Martin O'Donnell has named Sir Hugh's first wife as "Nuala, a daughter of O’Neill",^[6][7] and states that she was the daughter of Shane O'Neill. Siobhán's mother had probably died by 1566.^[7]

Historian Helena Concannon believes Siobhán was born c. 1569,^[8] and that her mother was Iníon Dubh,^[9] whom her father married in 1569.^[2][10][11] However, Siobhán's marriage in 1574 makes that date of birth extremely unlikely.^[12][1][13]

Siobhán's most prominent full-sibling was Donal O'Donnell. He attempted to depose his father, and in September 1590's Battle of Doire Leathan, Donal was killed by Scottish Redshanks led by his step-mother Iníon Dubh.^[14][15] Siobhan's younger half-siblings included future clan chief Hugh Roe O'Donnell^[16] and Rory O'Donnell, 1st Earl of Tyrconnell.^[17]

From the late-1560s to early-1570s, Hugh O'Neill (then 3rd Baron Dungannon) allied with many neighbouring clans to strength his political position.^[3] Siobhán married Hugh in June 1574.^[18][1][4] Walter Devereux, 1st Earl of Essex, announced their marriage on 14 June.^[2] Hugh had annulled his first marriage earlier the same year, on the grounds of consanguinity.^[19] This was in order to cut ties with his first father-in-law, who had been arrested for treason.^[20]

In 1579,^[21] Hugh became frustrated with his failure to seize the title of The O'Neill from clan chief Turlough Luineach O'Neill.^[3] Hugh briefly repudiated his marriage to Siobhán,^[21] who had not yet born Hugh a male heir,^[3] and he prepared to wed a daughter of Turlough Luineach with the aim of becoming the O'Neill clan's tanist.^[22] In February 1579 it was reported that Hugh and Turlough "knit up such a league of friendship". However this alliance did not last long and the new marriage was called off.^[23] Hugh was bought off by a government commission^[22] who convinced Hugh that, due to Turlough's age and ill health, Turlough would probably die soon enough.^[24] This episode apparently convinced Hugh that his "fate was tied to that of O'Donnell" and he solidified his alliance with the O'Donnell clan by reconciling with Siobhán. However it is possible that his reconciliation with Siobhán was a calculated move to keep in the government's favour.^[23]

The O'Neill-O'Donnell clan alliance would develop further by 1587, by which time Siobhán's younger half-brother Hugh Roe was betrothed to Rose, O'Neill's daughter^[25][10][16] from an earlier marriage.^[26][27]

In a letter dated 31 January 1591, O'Neill informed Lord Burghley of Siobhán's recent death.^[28][29] He remarried to Anglo-Irish noblewoman Mabel Bagenal on 3 August 1591.^[30]

Siobhán and Hugh had two sons and multiple daughters:

• Margaret (fl. 1598) who married Richard Butler, 3rd Viscount Mountgarret^[31][32] sometime before 8 October 1596^[33]—possibly in October 1595.^[34]
• Sarah (fl. 1595–1602),^[b] who married Sir Arthur Magennis, 1st Viscount Iveagh^[36] sometime before 4 March 1595^[37] - possibly in 1590.^[38] Through Sarah, Siobhán is an ancestor to the Anglo-Irish Wellesley family.^[39][40]
• Mary (fl. 1608), who married Brian McHugh Og MacMahon.^[41][42] According to historian George Hill, she is the same woman who married Sir Ross McMahon.^[43][44]
• Alice^[c] (1583^[46] – c. 1665^[47]) who married Randal MacDonnell, 1st Earl of Antrim.^[48] She was younger than her sisters Sarah and Mary, and older than her brother Hugh.^[46]
• Hugh, 4th Baron Dungannon (c. 1585 – September 1609); he died in Rome and was buried in San Pietro in Montorio.^[49][50][51]
• Henry (c. 1586^[52][51] – 1610); he became a colonel of an Irish regiment in the Archduke's army.^[53][31]