Nigel Sheldon is one of the co-inventors of the wormhole technology and co-owners of CST, and hence one of the two most wealthy and powerful people in the Commonwealth (and thus, all of human history). A physics and administrative genius, Nigel is head of the Sheldon Dynasty and responsible for many key events in Commonwealth history.
Development of Wormhole Technology
Nigel first became famous when he and Ozzie Fernandez Isaacs invented wormhole technology and used it to travel to Mars, greeting an astonished space exploration team. He and Ozzie developed the technology, founding the Compression Space Transport corporation and helping launch human civilization across the stars. While Ozzie largely moved on to other interests, Nigel continued to build the corporation and his family, the Sheldon Dynasty.
During the Commonwealth Saga
Nigel was one of the key figures who participated in the Starflyer War. While initially a sceptic (like almost everyone else) he was instrumental in defeating the Prime threat as well as the Starflyer itself.
During the Chronicle of the Fallers
As the most powerful human alive, Nigel was approached by the Raiel to infiltrate the Void and gain intelligence from Makkathran, the only Raiel starship known to have survived the Raiel invasion of the Void 1,000,000 years ago. However Nigel already had plans to lead a colonization fleet outside the Commonwealth, and outside the galaxy, to found a new civilization. This, and the very low chance of surviving an attempt to infiltrate the Void, combined with an insatiable thirst for knowledge and adventure, led him to create a clone of himself, who infiltrated the Void, linked by dreams to Nigel's main body.
The Nigel duplicate ended up on Bienvenido, and fell in love with Kysandra Blair, a Bienvenido native. Driven by his talent and confidence, ultimately overthrew the existing government in order to gain access to quantum buster technology held in the royal palace. Nigel's duplicate sacrificed himself, believing incorrectly that setting off the quantum busters would destroy the Void.
In the Andromeda galaxy, Nigel's main consciousness believed Bienvendido destroyed and concentrated on creating his new civilization, until reunited with Kysandra at the end of the series.