Umar Ibn Al-Khattab (r.a.) married women not out of sexual desire, but because he wanted many children. For he himself said, "I do not approach women (for sex) out of lust. And had it not been for (the desire to have) children, I would not have cared at all whether or not I even saw a woman with my eye." Umar (r.a.) also said, "Verily, I force myself to have sex in the hope that Allah will bring forth from (my loins) a person that will glorify Allah and remember Him."
Reference: Book: The Biography of Umar Ibn Al-Khattab by Dr. Ali Muhammad As-Sallaabee (Chapter 1, page 42)