Algol II, also known simply as Algol, was the second planet in the Algol star system, in the Alpha Quadrant. Algol was the homeworld of the sentient Algolian species. They Algolians were advanced around 10,000 BCE, but their society collapsed and they would not recover until making contact with the Federation beginning in the 29th century.
The Algolians had built a Tier 5 society around 10,000 BCE, when they experienced a sudden societal collapse. They regressed to a pre-industrial state which they would not recover from until the early 28th century. By the 29th century, they had made contact with the Federation. The Algolians joined the Federation in 2950 CE and gained an embassy on the Citadel in 3036 CE.