Mael Seachlainn II

Mael Sechnaill
An imaginative sculpture depicting Máel Seachnaill
High King of Ireland
Reign	979 – 1002 (first reign)
Predecessor	Muirchertach mac Mael Sechnaill
Successor	Brian Boru
King of Mide
Reign	976 – 2 September 1022
Predecessor	Muirchertach mac Mael Sechnaill
Successor	Mael Sechnaill Got mac Mael Sechnaill
Born	949 Ireland
Died	2 September 1022 Lough Ennell, County Westmeath
Spouse	Gormflaith ingen Murchada Máel Muire ingen Amlaíb
Issue	Conchobar Flann Congalach Domnall Murchad Rua Muirchertach
House	Ua Néill
Father	Domnall Donn
Mother	Dúnfhlaith

Máel Sechnaill mac Domnaill (Modern Irish: Maolsheachlann Mac Domhnaill), also called Máel Sechnaill Mór, Máel Sechnaill II, and anglicized as Malachy McDonnell (949 – 2 September 1022), was King of Mide and High King of Ireland. His great victory at the Battle of Tara against Olaf Cuaran in 980 resulted in Gaelic control of the Kingdom of Dublin.

Máel Sechnaill belonged to the Clann Cholmáin branch of the Uí Néill dynasty. He was the grandson of Donnchad Donn, great-grandson of Flann Sinna and great-great-grandson of the first Máel Sechnaill, Máel Sechnaill mac Máele Ruanaid. The Kings of Tara or High Kings of Ireland had for centuries alternated between the various Uí Néill branches. By Máel Sechnaill's time this alternating succession passed between Clann Cholmáin in the south and the Cenél nEógain in the north, so that he succeeded Domnall ua Néill in 980. This system had survived previous challenges by outsiders including the kings of Ulster, Munster and Leinster, and the Viking invasions.

In 980 Olaf Cuarán, King of Dublin, summoned auxiliaries from Norse-ruled Scottish Isles and from Man and attacked Meath, but was defeated by Máel Sechnaill at Tara. Reginald, Olaf's heir, was killed. Máel Sechnaill followed up his victory with a siege of Dublin which surrendered after three days and nights. When Maél Sechnaill took Dublin in 980, according to Chronicon Scotorum, he freed all the slaves then residing in the city