Tuchet succeeded his eldest brother on 11 Oct. 1684. His older brother George, a Benedictine monk, had voluntarily surrendered his succession rights under the act of 1678 that formally restored the family’s English barony of Audley. Like his brother, he was known by his Irish title earl of Castlehaven. He was principally a military man, a Catholic royalist with influential connections at court, in Ireland and among the English peerage.
Little is known of Castlehaven’s early life. He was in Ireland in the mid 1630s associating with his brother James and his sisters, Frances and Dorothy, both of whom married close relatives of James Butler, marquess (later duke) of Ormond. After the outbreak of the Irish rebellion in 1641, when his brother James found himself in considerable difficulties with the Dublin government, Tuchet acted as an intermediary between the two parties. Unlike his brother, he managed to make his way to England and the king’s service during the Civil Wars and was one of those who helped Charles II escape after the battle of Worcester.
Tuchet’s marriage to Lady Mary Talbot linked him to two significant English Catholic families, the Arundells and the Talbots. In January 1674, Tuchet and other members of the Talbot family, petitioned the Lords on behalf of Charles Talbot, 12th earl (later duke) of Shrewsbury, a minor. Having detailed the ‘wicked and scandalous life’ led by George Villiers, 2nd duke of Buckingham, and his lover Anna-Marie, countess of Shrewsbury, the boy’s mother, the petitioners asked the Lords to protect and relieve the suffering of the young earl.
After the Restoration, Tuchet joined his brother in a petition to Charles II requesting a grant of the waste and encroached lands belonging to the Crown in several counties, a petition renewed in April 1662 and possibly 1664.
On 10 May 1678 Tuchet’s name appeared on a draft order of witnesses to be called on behalf of the imprisoned popish lords. On 26 Mar. 1679 he was authorized by the Lords to visit London and Westminster for one month to take care of some personal business. On 12 Apr. 1679 Tuchet and his wife were ordered to be exempted from the bill for the better discovery and more speedy conviction of popish recusants owing to his role in preserving the king from capture in 1651; a proviso required Tuchet and the others only to take the oath of allegiance and not subscribe to the declaration against transubstantiation.
Upon succeeding his brother in October 1684, Castlehaven wrote to George Legge, Baron Dartmouth, requesting the continuation of the Irish pension his brother had received.
On 12 Mar. 1686 Castlehaven’s name appeared in a warrant sent to the attorney-general authorising him and other Catholic noblemen to be dispensed from the travel restrictions imposed upon Catholics. On 12 Apr. 1686 a warrant was sent to the lord lieutenant of Ireland granting Castlehaven ‘in consideration of his loyal and faithful service to the crown’, an annuity of £500 during pleasure.
Unable to take the Test, Castlehaven was barred from the House. He died on 2 Nov. 1686, being succeeded by his eldest son James Tuchet, as 5th Baron Audley and 15th earl of Castlehaven [I].