Dalton (ドルトン)
Background
When Monkey D. Luffy and his crew came to Drum Island in search of a doctor to cure Nami of her illness during the mission to get Princess Nefertari Vivi to Alabasta Kingdom, they encountered Dalton and some men who thought they were here to rob the island. When asked about a doctor, the only one who could heal Nami was a witch named Dr. Kureha.
Even after Wapol returned and once again subdued him, the people and even the top 20 doctors continued to help out Dalton. He was later seriously wounded by Wapol because he defended the townsfolk from arrows lauched by one of Wapol's bodyguards. And he in turn then, even almost going to extreme measures such as planning to blow up Wapol's castle. Luckily, Luffy defeated Wapol and knocked him off the island, after which the people of Drum elected Dalton as their new king and renamed the island, Sakura Kingdom (inspiried from the special chemical created by Hilruk, which turned the snow pink).
He appears later in chapter 440, where he shows Doctor Kureha the new bounties of the Straw Hat Pirates. He doesn't live in the castle, preferring to live in the village.