Blackstar was started quite earlier than that still. (Back even to 2008) It was the first game that STS was working on for the PC, but had to scrap it after NCSoft cancelled their agreement with STS to publish it.
The announcement for the development of Star Legends was on February 10, 2011, and then the limited beta came out later that year in July.
I'm not sure where you are getting the April date though unless you got something mixed up with Pocket Legend's anniversary.
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