Discharged from the school on 1 May 1886, two months before his 16th birthday, Charles Dunbar set his sights on joining the military. He enlisted with the Seaforth Highlanders as a piper on 6 October 1886. He stood only 5 feet 3 inches tall — probably the result of a scanty diet during his childhood — but it was often said of him that he appeared taller than he was because of his stature, stance and demeanor. Fraser's Scottish Annual records that "he was fortunate that the commander of the Seaforth Highlanders at that time was Colonel Guinness, an officer who took exceptional pride in the efficiency of his pipe band.