Crena held a very special place in the Four Islands' history: it saw the beginnings of an alliance between them all known simply as... well... the Alliance.
The Alliance's main base was on Crena, now known as Credd Rock. The group, whose leaders consisted of those from its containing islands, was made to help keep peace. It even seemed to benefit Reffira for a time.
One day, a foul wind swept through, plaguing the inhabitants with a bad sickness. Even those who rarely ever got sick had caught it, and those in poor health surely met their fate at its hands. Many perished in its relentless course, and the illness shook the main foundation of the Alliance to its core.