"Semper Fidelis" is Latin for "always faithful." The U.S. Marine Corps chose the phrase as its motto in 1883 to signify that the Marines are a brotherhood and can depend on one another. The motto reminds Marines to always remain faithful to their mission, country and to the Corps.
Mottos used by the Marines before Semper Fidelis include "Fortitudine" and "Per Mare, Per Terram." Fortitudine means "with courage" and was used prior to the War of 1812. Per Mare, Per Terram means "by sea, by land" and was used until 1883. The eighth Commandant of the Marine Corps, Colonel Charles McCawley, suggested using Semper Fidelis as a motto. The motto is sometimes shortened to Semper Fi.
The Marines' official march is also called Semper Fidelis. The Marines' seal features the motto emblazoned on a ribbon, along with an eagle, globe and anchor.
The Marines' core values are honor, courage and commitment. Honor refers to the high ethical and moral standard expected of all Marines. Courage refers to being stronger than fear. Commitment refers to a Marine's determination to continue at all times.
The Officer Candidates School uses "Ducto Exemplo," which means "to lead by example," as its motto. The motto signifies that Marine leaders should embody the core values.