In the Highlander franchise, the in-universe origin of the immortals is unknown. They are people born at different times and in different places throughout history. They cannot have children, so it is not a gift that is passed down. When an immortal is born with such a gift seems to be random. In Highlander: Endgame, Connor MacLeod says, "In the days before memory, there were the immortals. We were with you then, and we are with you now... We are the seeds of legend, but our true origins are unknown. We simply are."