The royal family began with the first king of Deltora, Adin. After Adin reunited the tribes and won the Battle for Deltora, he was crowned king. All the tribes swore allegiance to him and his descendants. Adin realised that the Shadow Lord was defeated but not destroyed, and would invade Deltora again if he could, so Adin wore the Belt always and never let it out of his sight. Adin and his Toran wife, Zara, had five children, and the oldest of these became king after Adin's death.
After the death of Adin's child, (who, according to the third book in the second series, had only one child), Elstred became king. During his later years Elstred became fat with good living, and the Belt of Deltora was tight around his waist. His chief advisor convinced him that he need not wear the Belt all the time if it was uncomfortable for him. Elstred wore the Belt only five times during his reign.
After Elstred's death, his daughter Adina became queen. She followed the advice of her chief advisor and wore the Belt only three times during her reign. Soon it became the custom for the monarch to wear the Belt only during their coronation.
Before the palace of Del was built, by order of King Brandon, the royal family lived in the Forge in Del. Even though Brandon never lived to see the completion of the palace, Brandon moved into it before it was even finished.
During the time of Adin, the royal family's duties involved ruling Deltora, keeping good relations with Tora, and always wearing the Belt of Deltora to protect Deltora from invasion from the Shadowlands. But as the centuries passed and the chief advisors began to control the kings and queens, these duties were forgotten and a new set of rules were created, called 'the Rule'. Members of the royal family were taught to obey these rules.
After the defeat of the Shadow Lord during the time of King Lief, the royal family were obliged to protect the kingdom by wearing the Belt of Deltora and help their people recover from the Shadow Lord's tyranny.
The Rule was a collection of thousands of laws and customs created by the Chief Advisors of the monarchs of Deltora. The Rule governed the actions of the monarchs and influenced daily life. Although many rules paid homage to Adin and included many useful skills, its purpose was to manipulate the rulers into doing the Shadow Lord's will and to ignore their duties.