Following the Cromwellian conquest of Ireland, in 1654 Shaen was appointed a member of the commission for setting out lands in Connacht and County Clare for Irish opponents of Cromwell who were forcibly transported from their homes.
[1] Despite Shaen's association with the Cromwellian regime in Ireland, in October 1660, after the Stuart Restoration, he was appointed cessor, collector, and receiver general of Leinster for life.
[2] In late 1662, he was sent by the Duke of Ormond to London to request £60,000 from the English government of Charles II; the mission failed, but Shaen instead proposed to raise a loan on behalf of the king.
After this, he largely disappeared from public life, playing no part in the Williamite War in Ireland, although he represented Baltinglass in the Irish Commons from 1692 to 1695.
[4] Shaen died on 13 December 1695, and was succeeded in his extensive estates and baronetcy by his only child, Arthur, who sat in the Irish Commons for Lismore in every parliament from 1692 until his death.