Hugh Gavelagh O'Neill

Hugh Gavelagh MacShane O'Neill (; – January 1590) was a sixteenth-century Irish noble of the O'Neill dynasty, specifically the MacShane branch. He was executed on the orders of his cousin the Earl of Tyrone.

Family background Gavelagh was one of the many sons of Gaelic chief Shane O'Neill. Shane had captured Catherine MacLean, wife of Calvagh O'Donnell, and made her his mistress. Their son gained the name Gavelagh, meaning "Fettered", because he was born while his mother was held captive in chains.

All of the MacShanes were fostered by the O'Donnelly clan, per Gaelic tradition.

Succession dispute The O'Neills were the most powerful Gaelic Irish clan of their time, but by the mid-to-late sixteenth century, they had fallen into internal conflict due to a succession dispute. The clan split into two major septs: the MacShanes (sons of Shane) and the MacBarons (sons of Matthew, Shane's reputedly illegitimate brother). Matthew was assassinated by Shane's followers in 1558; John O'Hart stated that Gavelagh was hanged by Loughlin MacMurtogh and his brother, both natives of Fermanagh. 20th-century historian Robert Dunlop stated that "if [Tyrone] did not, as was asserted, hang [Gavelagh] with his own hands on a thorn tree, he procured a hangman from Cavan to execute him." Hiram Morgan stated conclusively that Gavelagh was hanged by the public executioners at Dungannon. 17th-century writer Philip O'Sullivan Beare stated that Tyrone had "a Meath-man acting as executioner" for this same reason.

Tyrone anticipated the charges against him, and proceeded to London where he sufficiently defended himself against England's Privy Council. The justification Tyrone gave was that Gavelagh was guilty of various robberies and murders. Tyrone thus re-entered the good graces of Elizabeth I.

Years later, it was claimed that William Warren had recommended Tyrone to hang Gavelagh.