|Archon of the Lyran Commonwealth|
|Parents||Tatyana Steiner (mother)|
|Children|| Giovanni Steiner|
Upon his mother's retirement in 2937, Marco reluctantly became ruler of the Commonwealth. A poet by trade, he despised politicians and only accepted the throne because of the public's fear of his violent and sadistic younger brother who was seen as potentially another Claudius Steiner.
Marco's short reign was most notable for him leading investigations into a hidden spy in the Lyran Commonwealth Armed Forces who was leaking crucial intelligence to the Free Worlds League. With the help of the Lyran Intelligence Corps the traitor Mikhail Tertren, a company commander in the 12th Lyran Regulars who had sold out to the Mariks, was uncovered but escaped and remained at large for many years before finally being killed while leading a 3rd Marik Militia invasion of Cavanaugh II in 2952.
|Archon of the Lyran Commonwealth
| Succeeded by|
- Handbook: House Steiner, p. 98, "Lyran Leadership Profile"
- House Steiner (The Lyran Commonwealth), p. 73-74