Daumine Rolune was a Neimoidian leader who was appointed as chief ruler of the Neimoidian race in 22 BBY. Not only did he have power over all the Neimoidian worlds, including Cato Neimoidia, he had influence over the Trade Federation itself.
After Asajj Ventress saved Neimoidian Rute Gunnay of the Separatist Council, Daumine met with Senator Lott Dodd and General Grievous on Cato Neimoidia. Along with the assistance of R9-Z3, the group planned to assassinate Nute Gunray, Rune Haako and Rute Gunnay. With their deaths, Daumine would gain total control of the Trade Federation, with Lott being senior partner, as promised. However, their plan failed. Nute managed to evade Grievous and his troops, Rute surrendered the deeds, but not his life, and R9 was defeated.
After Gunray, Haako, and Gunnay gained control of the deeds, Lott was forgiven for his crimes. Grievous did not surrender or deny his involvement but Nute did not dare anger him. Daumine was the only to flee, as he escaped in a Sheathipede-class transport shuttle.