Elstred was married at some point in his life, but his wife died shortly before Agra became the king's chief advisor. As the King of Deltora, Elstred was well-liked among the people, though his younger brother, Ballum, was even more popular. Elstred often took Ballum's advice over Agra's. For example, when Elstred gained weight later in his life and the Belt of Deltora grew uncomfortable around his waist, Agra suggested that the king remove the Belt for his comfort. Ballum, however, reminded Elstred that the Belt was Deltora's primary defence against the Shadow Lord; Elstred heeded his brother's counsel and continued to wear the Belt.
On Elstred's birthday, Ballum was terribly wounded when a magic trick he had prepared for his brother malfunctioned. Elstred tended to Ballum personally, staying at his brother's bedside day and night until Ballum began to recover. The accident left Ballum bitter and, after Ballum began wearing a mask to cover his scarred face, Elstred slowly began to grow uncomfortable around his brother. Elstred's uneasiness was exacerbated by Agra, who frequently reminded Elstred that it was difficult to know Ballum's motivations when his face was hidden behind a mask.
One day Agra discovered poison in a cup that Ballum was passing to Elstred and accused Ballum of trying to assassinate the king out of jealously and bitterness. Elstred, to Ballum's horror, believed Agra, and Ballum fled. With Ballum out of the way, Agra became Elstred's most trusted adviser, eventually convincing the king to remove the Belt of Deltora and only wear it on special occasions. After Elstred’s death, his daughter, Adina took the throne, and she too was manipulated by Agra.
Elstred set a precedent that all subsequent kings and queens of Deltora would follow, allowing the chief advisors—all servants of the Shadow Lord—to slowly gain more and more control over the royal family, weakening Deltora and ultimately leading to the Shadow Lord’s second invasion.
Many years after Elstred's death, his and Ballum’s story was recorded by Josef in Tales of Deltora. Elstred is also the reason that the Masked Ones despise the royal family; Ballum, their founder, never forgave Elstred for believing Agra's lies.
Elstred was mentioned when his and Ballum's story was recounted by Doom, who had heard it from Steven. Doom told Lief about Elstred, noting the similarity between how the Shadow Lord split up Elstred and Ballum compared to Jarred and King Endon's separation.
Elstred was known to have gained weight during his time as King of Deltora, to the point that the Belt of Deltora became uncomfortable to wear. Elstred stopped wearing the Belt of Deltora regularly after Ballum's exile, only wearing it on special occasions.
Elstred was a comfortable man with a love of food and wine. He was loved by his people for his kindness. He was not a jealous or spiteful person; though the people of Deltora loved Ballum more than their king, Elstred was proud of his brother and trusted his judgment. He loved his brother deeply, never leaving Ballum's side as he recovered from his accident. However, Elstred was not particularly clever or strong-willed. When Ballum's disposition soured, Agra was able to convince Elstred that his brother was dangerous with relative ease. Elstred was easily controlled without Ballum to remind him of his duty to Deltora. While Elstred was kind, he was also easily led, and valued having a peaceful life over thinking for himself.
As one of Adin's heirs, he was able to wear the Belt of Deltora to defend his kingdom. As the King of Deltora, Elstred had access to large contingents of guards to defend himself and hunt down criminals, and presumably had a degree of control over all of Deltora.
Despite these luxuries, Elstred's overall talents were very lacking, especially when compared to his exceptional younger brother.