Charles Widmore
The DHARMA Initiative began to decline around the 1980s (most likely following the "Incident"), and was virtually destroyed in 1992 when Benjamin Linus facilitated a massacre of the group, named "the Purge", orchestrated by Richard Alpert and the leader of the Others at the time (probably Charles Widmore, who is shown interacting with Benjamin Linus before the Purge, and is generally known for his ruthlessness). Its facilities were left behind, some of which the Others claimed as their own. As a result of time travel, some of the survivors of Flight 815 become directly involved with The DHARMA Initiative, joining the program in the mid-1970s during the height of its power.