On the military side, O'Neill was also sidelined. After his disastrous defeat on 16 July 1642 at Glenmaquin near Raphoe in County Donegal against the Protestant Laggan Army led by Sir Robert Stewart, his kinsman, Owen Roe O'Neill, a professional soldier, arrived from the Spanish Netherlands and was made general of the Confederate's Ulster army. Felim O'Neill was a cavalry commander in this force, and spent most of the next six years fighting against the Scottish Covenanter army that had landed in Ulster. He fought in the army's victory at the Battle of Benburb on 5 June 1646.