From Halopedia, the Halo wiki
The Keyes family was composed of legendary family members who turned the tide of the Human-Covenant War and were remembered as war heroes, with the exception of Dr. Catherine Elizabeth Halsey, who was labeled as a war criminal despite being instrumental in the creation of the Spartan-II Program and Cortana.
Jacob Keyes was born on Earth and had a sister that lived on Dwarka. As a young lieutenant he met with Catherine Halsey who developed the Spartan-II program. The two of them had a child together, Miranda Keyes. Jacob Keyes developed the Keyes Loop tactic and eventually became a renown captain after many years. He died leading the Battle of Installation 04. His daughter Miranda had become a commander and worked closely with the UNSC's leader, Fleet Admiral Lord Terrence Hood, and led the final battle of the Human-Covenant War where she too died in combat.
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