who is jacob in lost

Jacob is a fictional character from the ABC television series Lost, portrayed by Mark Pellegrino. He is the ageless protector of the Island and plays a central role in the show's mythology. Jacob was first mentioned as the true leader of the Others and made his first physical appearance in the season five finale. He is known for his supernatural powers like immortality, healing, and the ability to change people's destinies. Jacob's backstory reveals that he was born on the Island to a Roman woman who was shipwrecked there in ancient times and was raised by a mysterious protector known as "Mother." He has a twin brother, who becomes the Man in Black, the show's antagonist. Jacob's long-standing conflict with his brother revolves around protecting the Island and the philosophical debate on human nature — whether humanity is inherently good, as Jacob believes, or corrupt, as his brother contends. Jacob has influenced the lives of many main characters by bringing them to the Island, including Jack, Kate, Locke, Sawyer, and Hurley, as he sought successors to take over his duties as protector. His eventual death leads to a transfer of this responsibility to Jack Shephard. Throughout the series, Jacob is central to the battle for the Island's future and to the ultimate resolution of the show's themes of fate versus free will.