Katheryn of Berain (Welsh: Catrin o Ferain) (born 1535 - Latin eulogy; died aged 56 on 27 August 1591), sometimes called Mam Cymru ("mother of Wales"), was a Welsh noblewoman noted for her four marriages and her extensive network of descendants and relations.
She is sometimes referred to as Katheryn Tudor, her father being Tudor ap Robert Vychan and her mother Jane Velville. Her maternal grandfather Sir Roland de Velville (1474 – 25 June 1535), is said to have been a natural son of King Henry VII of England by a Breton lady. Katheryn, who is said to have been a ward of queen Elizabeth, was the heiress to the Berain and Penymynydd estates in Denbighshire and Anglesey.
At the age of 22, Katheryn married John Salusbury, Esquire, son of Sir John Salusbury of Llewenni (died 1578), of the prestigious Salusbury Family of Lleweni, Denbighshire. According to John Ballinger, this was probably a "child marriage". There is said to be a letter written by young Salusbury while at Westminster School in which he mentions his wife. He died in late May or early June 1566. They had been married for nine years and had two sons:
Following her first husband's death, Katheryn married Sir Richard Clough, an extremely wealthy merchant, who established the Royal Exchange in the City of London with his business partner Sir Thomas Gresham. Clough had lived in Antwerp, and upon his return to Denbighshire in 1567 he built two houses, Bach-y-graig and Plas Clough. The houses were built in Antwerp style by Flemish craftsmen and were the first brick houses in Wales. Upon Clough's death Plas Clough was inherited by Richard Clough, his son by his first wife.
Katheryn had two daughters by Clough:
The Cloughs lived for a time in Antwerp, where Katheryn's portrait was painted, probably by Adriaen van Cronenburgh, as the National Museum now suggests, or perhaps by Lucas de Heere, a previous attribution. Within six years of their marriage, Sir Richard Clough died in Hamburg aged forty. He was probably poisoned because of his work as a spy for Queen Elizabeth I.