The Battle for Earth was a large-scale space, air, and ground battle between the invading Covenant forces and the UNSC Home Fleet on and around Earth at the end of 2552.

The Battle of Installation 05 was an engagement between the Covenant forces, including those that fled the Battle for Earth, High Charity, and the Second Fleet of Homogeneous Clarity, and the UNSC-allied forces, including the UNSC In Amber Clad led by Miranda Keyes, and the Fleet of Retribution led by the Arbiter Thel 'Vadam.

The Great Schism was a conflict between the forces loyal to the Covenant, led mostly by the Jiralhanae, and the Sangheili, beginning on November 3rd, 2552 and continuing off and on until the Rule of the Created in 2558.