Solomon-069 was a genetically, intellectually, and physically gifted child chosen for the SPARTAN-II project. He was known to be aggressive and headstrong amongst his peers. He was abducted by the Office of Naval Intelligence and replaced with a flash clone when he was around six years old.
Sixteen Spartan-IIs are known to have survived the Covenant War: John-117, Frederic-104, Kelly-087, Linda-058, Naomi-010, Jai-006, Adriana-111, Michael-120, Leon-011, Robert-025, August-099, Randall-037, Otto-031, Victor-101, Margaret-053, and Roma-143; the last five have since been killed.
Kelly-087 is a Petty Officer, First Class and is known as the fastest Spartan in the entire Spartan-II program. She is one of the original members of Blue Team, and served as a member of the team throughout the Human-Covenant War and the post-war period.
After changing his appearance, name, and removing things such as his fingerprints, he was then put back into ONI as a new member, and his original identity as Nathan Pete Walters was listed as MIA. Peter chose the tag -001 once the Spartan I project finished up.
Yûko was kidnapped and replaced by a flash clone at the age of 6 for the SPARTAN-II project. Though physically the weakest of any of the SPARTANS she was still physically stronger than a normal human. Her main strength lay in her mind.
1 Verdict: Master Chief
Both Master Chief and Noble Six are respectable and capable Spartans. However, when considering every factor, one soldier stands well above the other. Master Chief is the superior Spartan overall. His exploits, attitude, and skill are known and respected by many.
Though Spartan B-312 is forever known as Noble 6, they did not always have that title. The original Noble 6 was another Spartan by the name of Thom-A293. Thom-A293 may at first seem like a random character but he was actually the main focus of the Deliver Hope trailer which was set before the events of Reach.
SPARTAN-003, or Mike, was a SPARTAN supersoldier, of the SPARTAN-II Program's 1st Generation, and a part of the NavSpecWar group in the UNSCDF, and at times, an ONI operative, under the designation TRIAD.
76 Spartans were also killed at Laconia Station by Cortana in Halo 5, so out of the estimated 7,150 troops on The Infinity, Master Chief appears to be the only Spartan to have survived.
Sergeant Major Johnson is the most prominent SPARTAN-I in the series, and also the only one to appear in the games. However, it is not impossible that some of the anonymous special forces personnel encountered such as Orbital Drop Shock Troopers could have been ORION veterans.
Admiral Serin "Oz" Osman, born Serin Çelik and formerly known as SPARTAN-019, (service number 39489-72738-SO) is the Commander-in-Chief of the Office of Naval Intelligence, inheriting the role from Admiral Margaret Parangosky after the end of the Human-Covenant War.
Leonidas was Sparta's legendary warrior king, who with his three hundred brave warriors defended the narrow pass at Thermopylae against the mighty Persian king Xerxes.
The battle took place in the vicinity of Leuctra, a village in Boeotia in the territory of Thespiae. The Theban victory shattered Sparta's immense influence over the Greek peninsula, which Sparta had gained with its victory in the Peloponnesian War a generation earlier.
After taking on an enormous force of Sangheili and Unggoy, the Spartan was eventually outnumbered and mortally wounded by plasma fire, yet continued fighting even after being disarmed. Noble Six was finally pinned to the ground and killed by a group of high-ranking Sangheili.
Cortana chose Noble 6(and if you read Halsey's journal that is a single of two fragments of Cortana) to transport her safely to the Autumn.
Throughout the story of Halo Reach, we learn a lot about the intriguing protagonist, Noble Six, who is described in the early game as being a "more of a hyper-lethal vector than a soldier." Other than there only being two Spartans with that designation of "hyper-lethal," this term is never given a proper explanation.
Breaking the common trend of Spartan-IIs, Noble Six is easily the deadliest Spartan-III to ever grace the Halo universe. He is the only Spartan-III that has been classified as hyper-lethal, a title that was only held by one Spartan-II before 343 Industries retconned this detail.
Even if there could be Spartan reinforcements somewhere, their training station was destroyed by The Created AI Leonidas on the orders of Cortana, costing the lives of 76 Spartans along with hundreds of research staff in a violent explosion, and causing a massive setback to the Spartan Program and the UNSC as a whole.
Leonidas, (died 480 bc, Thermopylae, Locris [Greece]), Spartan king whose stand against the invading Persian army at the pass of Thermopylae in central Greece is one of the enduring tales of Greek heroism, invoked throughout Western history as the epitome of bravery exhibited against overwhelming odds.
The hippeis belonged to the first mora and were the Spartan army's elite, being deployed on the honorary right side of the battle line.