Archmage Jacob Swift left the Tower to a young arcanist Duran Sane who, in his very first few years, successfully saved the islands portal system in cooperation with mainland arcanists.
Duran Sane also managed to increase the interest in the Tower in his first few years, but his friendship with Ayin Mesmer and often being difficult to reach left many old members of the Tower outside, without renewing memberships. This included many officials of Light Keep, Bendir Dale and Cordor. Within the new members however, Duran found a couple of skilled assistants for the Conclave, among them Master Zanthir who became part of the Towers administration.
During the Wharftown incident Duran Sane stayed out of Wharftown, cutting his political ties to Ayin Mesmers government, at least officially, as the Archmage Kathele Meilea Se'Lhane-led army freed Wharftown. Duran was himself a resident there at the time. In the next few years, Duran Sane became difficult to reach for many members as well as many new applicants, and the Towers activity lessened to a crawl. During the event of Wharftown, Durans friendship with Ayin Mesmer, along with Archmage Se'Lhanes persistence to stay as a Safeguard of the Towers Spellhold, as well as Duran's fear that she might attempt to take the Tower over during his inactivity, led Duran Sane to completely cut all memberships temporarily, to ensure Archmage Se'Lhane's membership was removed.
Such a move was cause for much conflict and discussion, for Archmage Se'Lhane had worked for the Towers benefit for years and despite numerous chances, did not grab the reigns herself and focused more on governments-supported lecture series and teachings. Controversy followed in many public circles and the consequences to this decision spawned across all corners of the island. This includes official documents from the government of Myon, denouncing the Arcane Tower as long as it stays under leadership of Duran Sane and preventing Myon elves, and many elven kin in general, from joining the Tower. This action was a result of Duran Sane's sanctioning visits into sacred elven burial grounds without Myons approval and presence.
As a counter-move by Sane, Archmage Se'Lhane was also exiled from Cordor, her home, by the order of Ayin Mesmer who had been made the second in command in the Tower at that point. These events are considered the 'fall' of the Arcane Order Conclave and its traditions, that had lived from the very early days of Thoramind, replaced with a one-man rule, who alone appointed new leaders. This is quite different from the traditional Conclave which required the vote of trust from other settlements in the name of neutrality. A memorial was erected near Skull Crags by the followers of the Clergy of Mystra and Archmage Se'Lhane, to celebrate the history of the Old Conclave. This Shrine was maintained and taken care of by Maar and other surviving Mystrans, after Archmage Se'Lhane had left the island. This event marks a spiritual end to the traditional Conclave rule which lasted for many generations.