Timeline of the Black Mesa incident

Timeline of the Xen Invasion
	Black Mesa Incident; (up to 8 December 2000); North American Xen Invasion; (December 9 – December 14 2000 ); Extended Invasion (South America, Europe, Africa and North Asia); (December 14 – December 25 2000); Late Stage Xen Invasion; (December 25 – January 14 2000 ); Combine Invasion; (January 15 2000);

This timeline of the Xen Invasion covers the period from 6 December 2000 to the present day (January 18, 2001).

Post-Black Mesa incident (Up to December 8)