Sir Robert's great-grandson, Robert Preston, was created Viscount Gormanston in 1478; and the latter's great-grandson was Christopher, 4th Viscount Gormanston (d. 1599), whose second son was Thomas Preston, Viscount Tara. The latter was in the same Irish regiment in the Spanish service as Owen Roe O'Neill, and distinguished himself in the defence of Louvain against the French and Dutch in 1635. Between him and Owen Roe O'Neill there was from the first intense jealousy. Preston, who was appointed general of Leinster, took a prominent and not unsuccessful part in the war of factions that raged intermittently in Ireland from 1642 to 1652.
In 1650 Charles II while in exile created him Viscount Tara; and after his departure from Ireland in 1652 he offered his services to Charles in Paris, where he died in October 1655. His wife was a Flemish lady of rank, by whom he had several children, one of his daughters being the second wife of Sir Phelim O'Neill. His son Anthony succeeded him as 2nd Viscount Tara, a title that became extinct on the death of Thomas, 3rd Viscount, in 1674.
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