A Roman legion (from Latin legio "military levy, conscription," from legere — "to choose") normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but were typically composed of up to 5,000 soldiers, originally divided into maniples and later into cohorts. Maniples/Cohorts were divided into centuries.

In reference to the early Kingdom of Rome (as opposed to the republic or empire) "the legion" means the entire Roman army.

For most of the Roman Imperial period, the legions were a part of the Imperial army and formed its elite heavy infantry, recruited exclusively from Roman citizens (provincials who aspired to the citizenship gained it when honorably discharged from the auxiliaries). Each legion always included a small cavalry attachment. The Roman army (for most of the Imperial period) consisted mostly of "auxiliary" cohorts who provided additional infantry, and the vast majority of the Roman army's cavalry.

Mykel "Myke" Hawke (born November 29, 1965) is a retired U.S. Army Special Forces officer. He is best known for his role in the Discovery Channel series Man, Woman, Wild, where he co-stars with his wife, Ruth England, a British television presenter and actress. He is the author of several books, most recently Hawke's Green Beret Survival Manual. He holds a Bachelor of Science degree in biology from New York University and a Master of Science degree in psychology from the University of California, Santa Barbara. As a combat veteran Hawke was an enlisted Green Beret and later commissioned as a captain in special forces. He fought rebels and trained UN peacekeepers in war torn Africa and did combat search and rescue during the drug war in Colombia. Also of note he has earned black belts in Aikido and Judo.

Mykel Hawke also hosts the Discovery Channel show, One Man Army, in which personnel from backgrounds such as special operations, military, law enforcement, and extreme sports, compete in three areas of speed, strength, and intelligence to win prize money.