Sembla was located within a star system in the Sertar sector of the Outer Rim Territories region of the galaxy, away from any major trade routes. Its surface was covered with shallow seas and volcanic islands. There were vast gardens of coral and valuable crystal in the hottest of Sembla's oceans, and these were often targeted by off-world miners. Due to the nomadic nature of its indigenous species, the Vurks, there were few permanent settlements on Sembla. Ancient subaquatic ruins were known to exist along the planet's equator. These ruins did not appear to be Vurk creations, nor did the Vurks have any memories of established permanent settlements.
Sembla, known as Utavurk at the time, became part of Xim the Despot's empire at some point between 25,126 and 25,116 BBY. The planet was part of the explored galaxy by 20,000 BBY.
Sembla was represented by Sweitt Concorkill in the Galactic Senate of the Republic during the Clone Wars. After the Battle of Endor, Sembla remained politically unaligned and was not very involved in the galactic community. As a fortunate result, it was ignored by the Yuuzhan Vong.