From Halopedia, the Halo wiki
Hat Yai was a lightly populated human Outer Colony of the Unified Earth Government. The world was notable for its environment, which was characterized by tropical jungles, rain forests, and high humidity. The planet had one main continent.
In 2528 or 2529,[Note 1] Hat Yai was the location of one of the earlier battles of the Human-Covenant War, during which many Orbital Drop Shock Troopers saw their first combat against the Covenant. Before the battle, most of the civilian population was killed by Covenant invaders. Despite success against the Covenant by UNSC ground forces, the UNSC Navy was defeated and the planet was glassed by the victorious Covenant.
At some point either towards the end or after the Covenant War, Jameson Locke participated in Operation: DELHI, which saw the destruction of twenty-one special technical assets under the control of insurrectionist forces on Hat Yai.
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