Prior to the beginning of the trilogy, Lord Asriel had been a highly respected member of the 'Brytish' aristocracy. He had been an explorer and did work in "experimental theology", through which he acquired much power, land, and money. After having an affair with another politician's wife,
Marisa Coulter, that resulted in the birth of
Lyra, his life changed. Mrs Coulter's husband, Edward Coulter, attacked Lyra and her foster mother intending to harm and possibly murder Lyra. Lord Asriel intervened and killed Coulter. When the church found out, Asriel was tried and lost all property. Six-month-old Lyra was sent to a convent. Lord Asriel, who hated the church, arrived one day and took Lyra to his
alma mater,
Jordan College, where she was brought up believing Asriel to be her uncle, rather than her father. At the beginning of the trilogy, Lord Asriel visits Jordan College where he is almost poisoned by the Master. Asriel is saved by Lyra, who has secretly been watching the Master pour the poison into Lord Asriel's wine glass. Asriel is giving a Lecture to the Fellows of Jordan College hoping to raise money for an expedition. In the lecture he uses photograms of Dust and a city in the sky, as well as a severed head that he says is
Stanislaus Grumman's. He travels to
Svalbard but is imprisoned and guarded by the bear warriors known as the
panserbjørne, led by
Iofur Raknison. This action has been ordered by the General Oblation Board, which is headed by his ex-lover, Marisa Coulter. He receives hospitable treatment, and waits for a child on whom to perform intercision (a process to detach a child's dæmon that often results in the child's death). He is hoping to open a window in the aurora using the energy generated by the intercision in order to travel into a different universe. Eventually a child arrives,
Roger Parslow, unwittingly brought by Lyra. Asriel enters
Cittàgazze and, after a battle, allies himself with the rebel angels under
Xaphania. He travels to an empty world and builds an enormous basalt fortress, gathering armies from many different worlds to start his rebellion against the Kingdom of Heaven.
Ruta Skadi finds him, and he tells her his plan, and gets her clan's support in the war. Later, he has his allies, King Ogunwe and Lord Roke, find and rescue Lyra from Mrs Coulter. They capture Mrs Coulter, but Lyra and Will escape with two of Lord Roke's agents. Lord Asriel then attends to Mrs Coulter and tries to influence Lyra and Will, as they hold the key to renewing the Dust flow. Lord Asriel lets Mrs Coulter escape in an 'Intention Craft' and has Lord Roke follow her to gain information from the Consistorial Court of Discipline. They learn that the Church has made a bomb to kill Lyra, and Lord Asriel rescues Mrs Coulter just in time. He destroys Saint-Jean Les Eaux (the location of the bomb) with his Intention Craft. Lyra survives, and Lord Asriel has his army search for her and Will's dæmons so the Authority's armies will be unable to control them. When Lord Asriel finds that the bomb has blown a hole under all the worlds into the
abyss, he devises a plan to defeat the Authority's powerful Regent,
Metatron. As his forces fight the armies of the Authority and the Church, Mrs Coulter tricks Metatron into trying to kill Lord Asriel and to take Lyra's dæmon. As they are standing on the edge of the abyss, Lord Asriel and Mrs Coulter sacrifice themselves, falling into the abyss and taking Metatron with them. All three are condemned to fall through the abyss for eternity. ==Lyra and Marisa Coulter==