Hugh Roe McMahon (Irish: Aodh Rua Mac Mathúna; died September/October 1590) was an Irish Gaelic nobleman and Lord of Monaghan who reigned over Airgíalla from 1589 until his execution in 1590.
[2] Upon Ross's death, two of his kinsman had claims to the chieftainship: Hugh Roe McMahon was supported by English law (per the surrender and regrant policy) and Brian McHugh Oge McMahon was supported by brehon law.
The English Lord Deputy of Ireland, William FitzWilliam, planned to divide Monaghan between the claimants, preventing a potentially bloody succession dispute and also weakening the McMahon clan.
[1] After Ross's death, Hugh Roe McMahon went to Dublin to claim his inheritance.
McMahon objected violently, but was threatened with a charge of treason and so ultimately accepted.