Estin is a wildling and the main character and voice for both In Wilder Lands and Into the Desert Wilds.
Though he was born near Altis, his family's breed is unknown to the region. Estin's belief is that he is the last of his breed in the region, after spending part of his life looking for any signs of his lost father, mother, and sister. Though he believes his parents to have been killed by furriers, he holds out hope that he might one day find his sister.
The only home he has ever known is the Grinder--a section of Altis known for crime and violence. Given Altis' disregard for wildlings, Estin's life has been anything but pleasant.
Estin's motivations are a major factor in In Wilder Lands, driving him from initially just trying to make ends meet and survive, to the more mature goals of keeping his loved ones safe.
At the start of In Wilder Lands, Estin is approximately six years old (that's around 20-22 in human years). At the start of Into the Desert Wilds, Estin is approximately ten years old (around 33-36 in human years).