 Meanwhile, Tyrone's victory at the battle of Yellow Ford was followed by the spread of disaffection into Thomond's country.Teige O'Brien, Thomond's next brother, entered into communication with Tyrone's son, and joined the rebels.In 1599 O'Donnell invaded Clare, ravaging the country, capturing most of the castles, and making a prisoner of Thomond's youngest brother, Daniel O'Brien, afterwards first Viscount Clare, who had been left to defend it.