Mikah was a deckhand in the Rosalyn fleet as a young boy. He fled Deltora along with the fleet on the day the Shadow Lord invaded, and lived in exile for sixteen years. At some point he became a captain, and befriended Dare Larsett.
When Dare became an independent trader and owned the Star of Deltora, Mikah was its captain. He captained the ship on its maiden journey to find the Staff of Tier. Larsett successfully obtained the Staff and locked it in the ship's cargo hold, but Mikah was power-hungry and could not resist the call. He tricked Larsett, telling him he must use the Staff to heal his maimed hand. When Larsett agreed to touch the Staff once more and use it to heal the captain, Mikah cut off Dare Larsett's hand and fused it to his own arm, claiming the Staff for himself. After claiming the Staff and killing Larsett, Mikah sailed to the Isle of Tier.
Mikah placed Larsett's skeleton at the helm of the Star and wrote a note claiming the skeleton was his and framing Larsett for betraying the crew and awakening the Isle of Tier.
Larsett's skeleton was subsequently buried at the Del harbour graveyard with a gravestone bearing Mikah's name, reading: "Beneath this stone lies Mikah, 45 years, first Captain of the Star of Deltora. Foully betrayed by one he trusted, he perished attempting to bring his ship home. His courage will never be forgotten."
Mikah became increasingly nervous of Britta reaching the island and the wraiths felt this. He felt anger and shock as they revealed the ports that Britta would be visiting, the same ones he visited with Dare Larsett long ago.
Mikah feared he had lost power over the wraiths and they were being drawn to Britta. If Britta came close enough to the Isle she would be compelled to take up the Staff and become its new master. Though he could not speak of it to the wraiths, who would not understand his alarm, he did not want Britta to take his place.
Mikah is presumed to have been a capable sailor and captain, as he captained the Star of Deltora on its first voyage. As the King of Tier, he could control wraiths to some extent, cure all ills, live forever, and create objects out of nothing.