From Halopedia, the Halo wiki
Angoulême was once of the several cities on Meridian where Chalybs Defense Solutions had established production facilities. The standard-issue pilot helmet for the UNSC Air Force, developed by CDS, was designed and built from the ground up in Angoulême.
When the Covenant invaded the world in 2549, during the Battle of Meridian, Chalybs Defense Solutions abandoned their facilities on Meridian, though Angoulême was not among the cities initially targeted by the Covenant. However, by early 2551, Meridian was lost to the United Nations Space Command and Angoulême was likely glassed alongside most of the moon's surface and population centers.
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