 Munden was the posthumous son of Sir Richard Munden of Bromley St Leonard's, a captain in the Royal Navy, and his wife Susanna Gore.He broke with the family's naval tradition and was commissioned as a captain in the 1st Foot Guards in 1702.He served at the Battle of Blenheim in 1704, and after obtaining promotion to colonel in 1706, he fought later that year at the Battle of Ramillies.