In the Matrix films, Morpheus is the captain of the Nebuchadnezzar, which is a hovercraft of the human forces of the last human city, Zion, in a devastated world where most humans are grown by sentient machines and kept imprisoned in the Matrix, a virtual computer-generated world. Morpheus was once a human living inside the Matrix until he was freed.
Morpheus is apparently a very popular public figure in the city of Zion. He is also known in the Matrix, but as a dangerous terrorist wanted by ‘Agents’, who appear to be Federal investigators but are sentient computer programs that patrol the Matrix, eliminating any threat to the Matrix.
Like other hovercraft crews, Morpheus and his crew are dedicated to the protection of Zion and the freeing of humans from the Matrix.
Earlier in his life, Morpheus gained the romantic attention of Niobe, another hovercraft captain. Their relationship became estranged shortly after Morpheus visited the Oracle, an ally living in the Matrix, who told Morpheus that he would be the person who would find the One, a human having superhuman abilities within the Matrix who could end the human/machine war. Since that visit, Morpheus has spent much of his life searching the Matrix for the One.