Thomas Preston, 1st Viscount Tara, c.1585-1655
Veteran of the Spanish service who became a leading Confederate general, though his rivalry with Owen Roe O’Neill was detrimental to the Confederate cause.
Thomas Preston was the younger son of the fourth Viscount Gormanstown, a Catholic “Old English” nobleman of Dublin. In 1605, Preston joined Henry O’Neill’s Irish regiment in the Spanish army. He fought in the Spanish Netherlands and the Palatinate until 1625 when he left the Irish regiment on the outbreak of war between Spain and England. Preston’s reluctance to fight against King Charles was probably the cause of his quarrel with Owen Roe O’Neill, his acting regimental commander. Preston rejoined the Spanish service when peace was signed between England and Spain. He recruited his own regiment in Ireland and fought for Spain against the Dutch and the French until 1641.
In September 1641, Preston returned to Ireland to take part in the Confederate War. Through the influence of his kinsman the sixth Viscount Gormanstown, he was appointed commander of the army of Leinster, one of four regional Confederate commands. During 1642-3, Preston captured a number of forts in central Ireland to open a direct route between the Confederate capital Kilkenny and the western province of Connacht. However, the Leinster army was routed at the battle of Ross (Balinvegga) in March 1643 and was temporarily disbanded in August owning to a shortage of supplies and equipment. Preston’s greatest successes were as a siege commander, notably at the siege of Duncannon (Jan-Mar 1645), which he captured using the latest innovations in siege warfare.
In 1646, Preston was persuaded by Archbishop Rinnucini to reject the First Ormond Peaceand to join forces with his rival Owen Roe O’Neill to attack Dublin. Ormond’s intermediary the Marquis of Clanricarde opened negotiations with Preston, thus increasing O’Neill’s distrust of him and contributing to the failure of the Dublin campaign. The following year, Ormond surrendered Dublin to the English Parliamentarians commanded by Colonel Michael Jones. Preston was ordered to constrict Jones in Dublin and starve him of supplies. After capturing a number of outlying garrisons, Preston besieged Trim in July 1647. When Jones marched to relieve the siege, Preston attempted to outmanoeuvre him by making a forced march on Dublin, which was weakly defended in Jones’ absence. However, Preston was unable to outpace the Parliamentarian army and Jones inflicted a decisive defeat on him at the battle of Dungan’s Hill, in which almost the entire Leinster army was annihilated.
Preston took service with the Marquis of Ormond when he returned to Ireland to lead an alliance of Confederates and Royalists against the Parliamentarians in 1648. However, Preston was not given command of a field army. In 1650, he was created Viscount Tara and appointed governor of Waterford which he defended against Parliamentarian forces from June-August 1650. He was then appointed governor of Galway, which in April 1652 was the last Irish town to surrender to the Parliamentarians. With the ending of the Confederate War, Preston was allowed to leave Ireland for the Continent. He died in Paris in October 1655.
Thomas Preston married twice: his first wife, whom he married around 1612, was the daughter of the powerful Eycken family of Brabant; after her death he remarried in 1623 to a widow, Marguerite de Namur, who also predeceased him. He had three sons and six daughters. One of his daughters became the second wife of Sir Phelim O’Neill. His son Anthony succeeded him as the second Viscount Tara. The title became extinct on the death of the third viscount, Thomas, in 1674.
Pádraig Lenihan, Thomas Preston, first Viscount Tara, Oxford DNB, 2004
Pádraig Lenihan, Confederate Catholics at War 1641-49, (Cork 2001)