Mechanically and biologically augmented super-soldiers created by the
UNSC that exist in the Halo universe. The SPARTAN-II program began in 2517. Candidates for the SPARTAN-II project were
orphaned children. The SPARTAN-IIs quickly became the
UNSC's most effective weapon in the battle against the Insurrectionists. When the war with the Covenant Empire broke out, SPARTAN-IIs were equipped with the most advanced mechanized armor to deal with the aliens. The Insurrectionist movement and the war with the Covenant spurred Colonel Ackerson to
spearhead the SPARTAN-III project. The purpose of the SPARTAN-III project was to create cheaper, more expendable
Spartans at a faster rate. SPARTAN-IIIs were intended for extremely high-risk operations with a high level of secrecy. Once again
the Spartans would be taken from orphanages and trained from the age of 6. Throughout the Human-Covenant War, 3 companies of SPARTAN-IIIs would be deployed, one of which became trapped in the Shield World with the SPARTAN-II
Blue team after the Battle of Onyx. The SPARTAN-IV project was initiated by Admiral Parangosky after the Human-Covenant War, but instead of children, volunteers from the UNSC were used. Some of the SPARTAN-IVs were stationed on the UNSC Infinity where they participated in several engagements. Throughout all of
the SPARTAN projects, the UNSC lists any casualties as MIA or
WIA to enforce the belief that Spartans cannot be killed.