Chancellor of the Taranian people. Lycus's people inhabited and operated an Ancient installation on Taranis. He commenced and maintained relations with the Atlantis expedition approximately a year after his people had configured Taranis's Ancient shield to run continuously, when Wraith activity had increased.
Perhaps as a show of might, Chancellor Lycus showed John Sheppard's team his people's Ancient warship, concealed in a hangar beneath their base. This was a decision he almost immediately regretted. As seismic activity increased on Taranis it became apparent to him that the Atlanteans were intent on getting the warship for themselves.
Elizabeth Weir herself arrived to extend an olive branch, insisting that military might the likes of an Ancient warship was already possessed by her people. His suspicions intensified when Dr. Weir and her scientists insisted on evacuation of their settlement, as all of it was built in the caldera of a giant super-volcano. But Weir insisted that the Teranians would be in the same situation had they never sent out a call for help.
Lycus and Weir led the way back to Atlantis to greet refugees on the other side, but in the midst of the first wave the Stargate was lost in a pool of lava. The chancellor did not see this as coincidence, but as events un-spooled, the expedition's efforts to send the Daedalus to help his people eventually made Lycus realize he had been mistaken about his new allies.
The expedition aided in the resettlement of the Taranian people to a new home world, after the super volcano of Taranis made the world uninhabitable.
Inferno - Chancellor Lycus's distress calls are answered by Atlantis, who appear to be more interested in harnessing the power of the Taranian's Ancient warship rather than helping them fix their seismic problems.