Ertun was a lead representative from the Guild, sent to Arrakis in 10,194 AG, with his assistants, Loyxo and Crozeed, to request of the Emperor Paul Atreides, an increase of the allotment of melange to their organization. Ertun, like many members of the Guild, had human anomalies to his anatomy; in particular, he had an over-sized head, the left side which had a metal plate, and the other half had ragged orange hair.
When their delegation arrived in the Imperial Palace in Arrakeen, they were upset to find that Muad'Dib was on Caladan, and his four-year old sister, Alia was holding Court. As Ertun spoke out of turn to the future Regent, Alia told him to quiet himself, so that the lesser Guildman, Crozeed, could address the Imperial family. As Crozeed spoke of the Guild's need for spice, and CHOAM's concern for the loss of business that Paul's Jihad was causing throughout the Imperium; Ertun interrupted.
Ertun spoke of wanting to please the Emperor, then spoke of how the Guild's Navigator's were having a hard time seeing Paul's future, as there was so much chaos around Muad'Dib. Alia responded that the Guild should help Paul, to which he would be grateful; and then Ertun spoke of the Guild's neutrality. Alia reminded the Guild, as well as everyone in the Audience Chamber, that anyone who did not openly support the Atreides, were revealing themselves as enemies. Alia dismissed Ertun and his delegation and said that if the Guild dedicated two hundred ships to the Jihad, that the Guild would receive a 3% increase in melange.