Attack on Umbra
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The Attack on Umbra describes a sneak attack by the Cylons approximately 26 yahren before the Battle of Cimtar.
This raid was apparently one of the "first raids on Caprica", according to Chameleon, a survivor from this raid. As a result of this action, nearly three thousand children were orphaned, including Starbuck; his father had been the aforementioned Chameleon, who was unaware that his son had survived until he learned of it more than 26 years later (TOS: "The Man with Nine Lives").