Marcus was born in the suburbs of Washington D.C. at Alexandria hospital. His father was a Irish Strongman who masked the covers of fitness magazines throughout the 60's. His grandfather, Chief Turkey Tayac, of the Piscataway Indians, was the last chief who was born in the 19th century to die in the 20th. He is also the only Chief buried in a national park which took an act of Congress and a Supreme Court ruling. The burial grounds are in Piscataway, Maryland across the Potomac River from George Washington's home in Mt. Vernon Virginia. Marcus has a brother and sister and along with a couple uncles and cousins, they are the last of their tribe.

Shirock Graduated from Annandale High in '94, but before he left, he walked away with four football Championships including the State Title. He also ran away with three power lifting Championships including the Northern Region Title his senior year. After graduating high school he left his family and friends behind on the 4th of July to defend his country. Shirock joined the United States Marine Corps. He finished his Boot Camp at the Marines most famous Parris Island. After graduating with a perfect (PFT) physical fitness test score of 300 he went on to Ft. Sill, Oklahoma for Artillery Training.

After honorably leaving the Marines he moved on to Hollywood, California unknowing that an acting career would start the second day he arrived. While Shirock was on Sunset Blvd. doing a martial arts demonstration, a director walking by was caught off guard by his presence. The next thing you know it was lights, camera, action. He has been pursuing his acting career ever since and has studied since 1997 while appearing on the television shows such as 'Angel' and 'Charmed' and has worked on several major films. In 1999 Sam Raimi and 'Marvel Comics cast him as the prototype for the Superhero Spider-Man (2002). In 2005 he has a co-starring role in an original ensemble cast with Oscar award winning actor Jon Voight called _The Legend of Simon Conjurer (2006)_ due to premier in March 2006.

Marcus Shirock is a All-American true to his work and believes anything can be accomplished with hard work and perseverance. No drugs, alcohol or smoking are in his life.