Jeffrey Sinclair was the original Commander of the Alliance of Nations. He was the son of an Vektan citizen, Thomas Sinclair and Izzy Sinclair. He was one of the commanders in the decisive battle in Ciz'Lokki. He was also the commander of Babylon 5.
Jeffrey Sinclair was born on Mars on May 3, 1424 N.E, the son of a career military officer, David Sinclair, and a Professor of North American literature, Gemma Gildea Sinclair. Jeffrey also had a brother, Malcolm. His father flew for Earthforce during the Dilgar War and was eventually killed during the conflict, though not before being present at the liberation of Balos. According to Jeffery, his father never forgot what he saw there.
When Babylon 5 went online in 1559 N.E, Sinclair was chosen to be in charge of the station, even though several others were in line in front of him. Sinclair was surprised when they informed him, as he was comparatively low ranked compared to many of the other candidates. He would learn later that he was specifically chosen at the behest of the Minbari, who were the first to sign onto Babylon 5 but only on the condition they were allowed to choose the station commander.