The Serbian Army was essentially destroyed in 1915, and lost a massive amount of equipment. It was rebuilt with French assistance and reequipped with French arms in 1917, including about 5,000 Ruby pistols. These were standard French handguns at the time, and those that survived the rest of the war would remain in Yugoslav armories (as the Kingdom of Yugoslavia incorporated the former Serbian nation) well into the 1930s.

What we have today, courtesy of Mike Carrick from Arms Heritage magazine, is one of those Franco-Serbian Rubies, refurbished and remarked by Yugoslavia in 1933.