From Welsh Biography online

Sir ROGER MOSTYN ( 1623/4 - 1690 ), knight and baronet . Although he was only 19 years old when the Civil War broke out, he soon became a captain , and, within a few months, colonel , in the Royalist forces . Charles I also appointed him governor of Flint castle and town. For the next few years his personal history is intermixed with his activities as a Royalist officer — for details see the History ; J. R. Phillips , Civil War in Wales ; Calendar of Wynn Papers ; Whitelock , Memorials ; and Henry Taylor , ‘ The Flintshire Militia, with a short biography of Sir Roger Mostyn… its first Colonel ,’ in Jnl. of the Chester Archaeol. and Hist. Soc. , 1891 . His grandson estimated that his losses during the Civil War amounted to about £60,000. He was closely associated with the efforts made to restore the monarchy. In 1660 he was named as one of those qualified to be made a knight of the Royal Oak , created a baronet ( 3 Aug. 1660 ), and became a deputy-lieutenant for Flintshire . The duke of Beaufort , during his ‘Progress’ of 1684 as Lord President of Wales , was entertained by Sir Roger at Mostyn and spent Thursday, 24 July ‘ in viewing the lands and various works and Machines of the Lead & Colemines belonging to Sir Roger Mostyn . … ’ ( Thomas Dineley , The Beaufort Progress , where there are sketches of Mostyn Hall and of one of the ‘machines’). In 1687 queen Mary ( of Modena ) , the consort of James II , induced her husband to make a grant of S. Winifred's Chapel , Holywell , to her; the queen wrote to Sir Roger requesting him to arrange for her wishes in the matter to be carried out. Sir Roger d. at Mostyn , 4 Oct. 1690 . He had m. (1), c. July 1642 , Prudence , daughter of Sir Martin Lumley , (2) Mary , eldest daughter of Thomas , viscount Bulkeley , of Baron Hill , Anglesey , and (3), Lumley , eldest daughter of George Coetmor of Coetmor .