William Trayle was Member of Parliament (M.P.) for the County in 1376 and 1381.
Johannes Trayle was Chevalier M.P. for Bedford Borough in 1541.
Michael Thrayle appears as M.P. for the Bedford Borough  in 1541.
His son Henry Thrale  1730 - 1781 was also M.P. for Southwark between 23 December 1765 and September 1780 . He was re-elected after coming second in the in the 1768 and October 1774 general elections. Henry was a Tory - like all brewers - and was together with Samuel Johnson was a fervent supporter of Lord North . He was defeated in the 1780 election, which included an election address  which was written by Dr. Samuel Johnson .
One of Ralph Thrale's other children was Susannah Thrale . She was twice married, both times to MPs! Her first husband was Thomas Scott M.P. for Bridport 1780-1790. Her second husband was Arnold Nesbitt M.P. (died 1779) for Cricklade  between 1761-1768 and 1774-1779.
Queeney Thrale (Henry's eldest child) husband Viscount George Keith of Elphinstone  sat as Member of Parliament for Dunbarton  from 1781 - 1790, and later was M.P. for Stirlingshire  between 1796 and 1802.
It is speculated (by Hester Thrale in Thraliana  dated 1 March 1779) that Henry Thrale's sister Lady Mary Lade (1733-1802)  bore an illegitimate child for Colonel Sir Philip Jennings Clerke M.P. (died 1788) after the death of her husband Sir John Lade.1 This is not a definitive list, and there could well be further Thrale MPs. Please tell if you know of any others.