Richard Mack Sr.

"Sooner or later, your conscience is going to bother you. In the end, you have to choose whether you're going to live as a soldier, or just another man or woman with a gun"

- Mack addressing the young SPARTAN-II recruits in 2520

Richard Mack Senior, also known as Codename: LEONIDAS by ONI, was a member of the in the late 24th Century and the  for most of his adult life. Mack was one of the highest performing candidates while in the project and later emerged as a celebrated hero by the beginning of the 26th Century. He was also responsible for training the SPARTAN-II Sigma Team on Earth. Later, he would go on to lead UNSC forces against the Covenant on dozens of engagements over the years until his death in early 2552.