"Here I am, here I remain!" After almost two decades of rule on Caladan with the Lady Jessica, Leto was ordered by the Emperor to take over the planetary fief of Arrakis from House Harkonnen, and thus was required to move his House from Caladan to 'Dune'. Arrakis was a notoriously difficult planet to manage, but as the only source of the spice melange, it was also unimaginably important. Thus the role brought both jeopardy and the jealousy of Leto's fellow noblemen among the Great Houses. Thus, Leto leapt at the chance to increase his standing in the Landsraad, even though he knew it would also put his House in great peril. Leto committed all his resources to the venture, and it was said that to illustrate this point to his people and the people of Arrakis, that upon his arrival he planted a flag upon the battlements at Arrakeen and proclaimed: "Here I am, here I remain!"

Leto's resolve was strengthened by a letter the Emperor had sent him upon his Arrival on Arrakis. Addressed to his "Noble Duke", the letter outlined that Leto was given House Corrino's full support to introduce and uphold the rule of the Faufreluches. This letter served to illustrate Corrino duplicity, for at the same time, Shaddam IV was plotting Leto's demise.

During consolidation of his rule over Arrakis, Leto made a quick and positive impact on the people of Dune. His fairhandedness, political savvy, and personal charisma saw many in Arrakeen society, from the Fremen to the aristocratic Houses Minor, become supporters. However, only a short while into Leto's rule on Dune, the Emperor gave Baron Vladimir Harkonnen approval to invade and destroy House Atreides, even going so far as to provide some of his own Sardaukar in support. The Emperor's urgency in disposing of House Atreides was amplified by the fact that he had come to know that the Duke Leto had managed to develop a small force of soldiers capable of rivalling the Emperor's Sardaukar. This had been accomplished through Leto's principal advisors and generals, namely Thufir Hawat, Duncan Idaho, and Gurney Halleck.