File:18 June 1815 – Waterloo – Mont-Saint-Jean, Entrance Gate.jpg

English: Mont-Saint-Jean farm (where farming activity at this location can be traced back to the 15th century) acquired its place in History in the aftermath of the 18 June 1815 Battle of Waterloo, when used intensively as field hospital by the Royal Army Medical Corps – assisted by local doctors and surgeons – who took care of about 6000 casualties, as a tablet recalls : ►(File:18_June_1815_–_Waterloo_–_Mont-Saint-Jean,_Tablet.jpg).

Sgt-Maj Edward Cotton, who fought at Waterloo – where he settled down and acted as a guide to visitors –, left to the posterity a precious account of the 3-day fights, a most valuable document for its humanity and balance. Talking about Lord Wellington who had just met Field-Marshall Blücher near Belle-Alliance, he reports : Our galant chief returned over the field to Waterloo, and (...) was so affected by the cries of the wounded and the moans of the dying, as to shed tears, and on his way did not exchange a word with any of his suite, composed only of five persons. (Excerpt from A Voice from Waterloo, 5th edition, 1854, 132)

Churches for sure also served as field hospitals, for instance : ►(File:18_June_1815_–_Victory_at_Waterloo_–_Braine-l'Alleud.jpg), and, northwards, beyond the then dense Sonian Forest, private houses, big and small, all the way to Brussels and in Brussels too.

Nowadays : the northern wing is a listed monument since 1995. The whole farm has been restored from 2011 to 2015 to coincide with the June 2015 bi-centenary commemorations of the Battle and the inuaguration of the British Ambulance Museum dedicated to the treatments in use by then on battlefields – museum managed since 2017 by a non-profit organization (ASBL Waterloo Ferme de Mont-Saint-Jean (Hôpital Britannique)).

Privately owned since 2014, Mont-Saint-Jean farm is still further transformed into a restaurant, and a leisure area extending to the east of the precinct.