Thomas Ridgeway, 1st Earl of Londonderry

He succeeded his father on 27 June 1597, and in July of that year fitted out a ship at his own cost to take part in the Essex-Raleigh Expedition under Robert Devereux, 2nd Earl of Essex.

In 1603, he had been appointed vice-treasurer and treasurer-at-wars in Ireland under Lord Deputy Sir George Cary, whom he eventually succeeded as treasurer in April 1606.

He assisted in the preliminary work of surveying the escheated counties of Ulster preparatory to the plantation, and on 30 November urged on Salisbury the necessity of putting the scheme into execution as speedily as possible.

On 31 July the commissioners set out from Dublin towards the north, returning about the beginning of October, but it was not until the end of February 1610 that the inquisitions taken by them were drawn up in legal form and the maps properly prepared.

Meanwhile, new commissioners, of whom he was one, had been appointed to carry the scheme into execution; and Ridgeway, as soon as he was relieved from attendance on the council, sailed over in a small boat of seven or eight tons.

Further, as a servitor, there was assigned to him another estate of two thousand acres (8 km2) in the precinct of Dungannon, County Tyrone, lying along the upper course of the Blackwater, and represented as abounding in woods and bog land.

He was one of the first to take out his letters patent, and from a report made of the state of the plantation in 1611, he appears to have been fairly active in fulfilling his obligations as an undertaker.

In anticipation of the intended calling of a Parliament of Ireland, and with the object of securing a majority in it for the new settlers, a number of boroughs were created in 1612, and on 13 November Ridgeway was constituted a burgess of Balinakill in Gallen-Ridgeway, Queen's County, of which place he was elected MP on 17 April 1613.

The transaction was nominally a sale, but strictly an exchange of the Portclare and Ballykillygirie estate for the title and dignity of an earldom, of which Erskine had the disposal.

In the Star chamber proceedings against Thomas Howard, 1st Earl of Suffolk in October 1619 one of the strongest pieces of evidence against him was a direct statement of Ridgeway that during the time he had been vice-treasurer he had never been able to obtain the money needed for the public service unless his demand was accompanied by a bribe.