Thornthwaite Hall was built in the second half of the 16th century and is an L-shaped two storey rubble built house with slate roof. The block at the south east angle was formerly a pele tower but is now used as a staircase wing. (PastScape–ref. RCHME)

In the Court of Requests there is a curious petition, dated 25 May, 1576, as follows:—Thomas Langhorne and others showing that whereas they and their ancestors time out of memory of man have quietly had and enjoyed possession of certain tenements according to ancient custom, in consideration of their service to be in readiness with horse, harness and other furniture to serve her majesty the Queen at their own cost and charges in defense of the realm against the Scots; but so it is that Sir Henry Curwen, lord of the lordship of Thornthwaite hath expelled twelve tenants and taken their land from them and hath enclosed it into his demesne and hath surrendered over the same lordship to Nicholas Curwen his son and heir." Have we not in this petition the first record of Thornthwaite Hall? Sir Henry providing an estate for his son whereon he could build for himself a home in imitation of a Border Pele. Nicholas was then 25 years of age and about to take to wife Anne, the daughter of Sir Simon Musgrave of Hartley Castle. Sir Nicholas died in 1604 and his son Sir Henry sold Thornthwaite to Lord William Howard, before 1612. Lord William used the Hall for convenience when hunting and he it was who built the banquetting hall. Francis Howard, who died in 1702, left the manor to his three daughters, the eldest of whom bought out the other two shares after marrying John Warwick, and their son Francis Warwick sold the manor to Edward Hasell of Dalemain, reserving to himself the Hall of which he died seised in the year 1772. The battlements were taken down last century and the tower, 31 by 27 feet, roofed over