Marc Isambard Brunel was born on 25 April 1769 at Hacqueville, near Gisors, Normandy, the second son of Jean Charles Brunel. 
Marc Isambard Brunel (bachelor) married Sarah Kingdom (spinster) on 1 November 1799 at St Andrew's Holborn, Middlesex, England.
Brunel spent 88 days incarcerated in a debtors prison in Southwark, the King's Bench Prison, in 1821.
↑ "England Marriages, 1538–1973 ," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:NJQZ-W92 : 10 February 2018), Marc Isambard Brunel and Sophia Kingdom, 01 Nov 1799; citing St. Andrew'S, Holborn, Middlesex, England, reference p159-2, index based upon data collected by the Genealogical Society of Utah, Salt Lake City; FHL microfilm 374,369.
Beamish, Richard. Memoir of the Life of Sir Marc Isambard Brunel, Civil Engineer, Vice-President of the Royal Society, Corresponding Member of the Institute of France, Etc. .. London, Longman, Green, Longman, and Roberts, 1862. Internet Archive