Dr Martin Lanselius was the diplomatic consul of the witches of the North, based in Trollesund. His dæmon had the form of a green snake. He had methods of passing on messages to witches under the Birch oath.
At some point after meeting Professor Gunnar Hallgrimsson, Lanselius met Coram van Texel, and he was able to later send Coram with a letter of introduction to meet the Swedish Professor, where they discussed the study of the Alethiometer.
After the General Oblation Board began abducting children, Lanselius assisted the East Anglian Gyptians by sending a message to Queen Serafina Pekkala of Lake Enara, who enlisted her people to help rescue the children from Bolvangar.
It was here that Lanselius was able to test Lyra Belacqua's skills at reading the Alethiometer and prove that she was a child prophesied by the witches.
Lanselius was a fat man with a florid face and vivid green eyes. He wore a sober black suit.
- Northern Lights
- Northern Lights - The Graphic Novel
- The Golden Compass (video game)
- The Subtle Knife
- Lyra's Oxford (Mentioned only)
- La Belle Sauvage (Mentioned only)