A ship captain in the starless void who joined Janeway's alliance, was expelled for piracy, and then joined Valen against her.
Bosaal is a captain trapped in the empty region of space in The Void. He calls Fantome's species vermin, but joins Janeway's alliance once she offers to take any of them off his ship. His contribution includes a polaron modulator that Voyager needs to escape the region.
When Janeway learns he obtained the device through piracy, she orders it removed and forces him off her ship. Bosaal then joins General Valen in forming a rival alliance and attacks the coalition, but the attack fails and the alliance escapes the Void.