Serrano was a planet in the Outer Rim Territories. One thousand years before the Battle Of Yavin it was governed by the six Great Houses to which the Counts of Serenno belonged; the Counts were amongst the wealthiest beings in the galaxy and believed in nobleness oblige and self-reliance.
Nearly a millennium later, Serenno gave rise to a far more dangerous rebel demagogue. Dooku was born on Serenno in 102 BBY. His family bore the title of Count and lived in a great house with rose bushes. Dooku once visited the seashell-littered shores of a Serenno ocean as a child.
After murdering Jedi Master Sifo-Dyas, Dooku stored his cryogenically frozen body on the planet, to be retrieved several years later for transportation to Geonosis, where a blood transfusion between the dead Jedi and Qymaen jai Sheelal occurred.
Serenno was a stronghold of Count Dooku during the Clone Wars.