[1] After his military education in a foreign army – according to the custom of that time – Carl Gustaf Roos participated in Charles XI of Sweden's war against Denmark.
After Charles XII's accession to the Swedish throne he served the new king in battle.
Roos distinguished himself at the battle of Narva in 1700 and was promoted to colonel, as well as head of the Närke-Värmland Regiment in 1701.
In 1706 Roos was promoted to Major General and participated as such in the battle of Poltava on 28 June 1709.
Roos died in 1722 on his way home from his release from captivity after the 1721 treaty of Nystad.