The main part of the collection consists of letters written by Edward M. Wrench whilst serving in the Crimea and in India. Together with similar letters amongst the material in the sub-fonds Wr, these provide a fascinating insight into the life of an army surgeon. In addition to letters from Edward M Wrench, there are also letters from others in the Crimea including his cousin John Henry Kirke (1833- 1892) (see also Wr Ki), John George Eschalez, and also a number of letters relating to hospitals in the Crimea. There are also a number of cyclostyled letters from Edward M Wrench to his children and a number of letters from Edward's son William Mervyn Wrench (1863-1890) in New Zealand. The latter are supplemented by a diary relating to William Mervyn's stay in New Zealand. The collection also includes copies of genealogical papers , notes, photographs, sketches and miscellaneous papers.
Much of the material was used by Edward Gillam Wrench in the 1950s and 1960s when he compiled a number of typescript volumes. These were prepared mainly for family members but five of the volumes of Edward Gillam Wrench are included within this collection. A further volume mainly of Kirke letters but also including trancsripts of letters from Edward M Wrench is present within the Kirke part of the Wrench collection (see Wr Ki)