Mons About share History lovers, you are in for a treat. The capital of Belgiumâs Hainaut Province (and the fourth-largest city in Wallonia), Mons has been the centre of attention so very many times since it was established in the 12th century by the marvellously-monikered Count Baldwin IV, who we presume was no relation to Alec, William and the rest. The city was occupied by a whoâs who of European leaders until the Industrial Revolution made it an even more desired prize, although such thoughts were far from the minds of British soldiers during World War Iâs Battle of Mons, the first battle the Brits were involved in during the Great War.