Origin: As the Others' leader, Ben had to follow Jacob's rules.
Since Then: Ben spent many years trying to serve the island though he never actually met Jacob. He pretended to speak with Jacob and often used his name to justify his actions. When the two finally did meet, Ben stabbed him to death for the years of neglect.
Origin: The two brothers lived together on the island till the Man in Black went to the other side to live with his people.
Prize: For The Man In Black it was leaving the island. For Jacob it was to protect the island which meant he had to keep his borhter from ever leaving and "spreading his evil".
Fuel: They met regularly over the next years. When the Man in Black killed their Mother, Jacob cast him into the Heart of the island, transforming him into the smoke monster. The two spent the next couple thousand years debating the nature of humanity and each seeking a loophole to let them kill the other. The Man in Black eventually succeeded, but Jacob's ghost continued to visit him, warning him against harming Jacob's candidates.
Resolved: No, The Man In Black convinced Ben to murder Jacob however Jacob's candidates were able to keep The Man In Black from leaving the island and were eventually able to kill him.
Origin: Richard tried to kill Jacob, thinking him the devil.
Since Then: Jacob convinced Richard that he was not the devil, and the island was not hell. He explained its purpose and hired Richard and an intermediary between himself and the people of the island. Richard served this role for almost 150 years. Jacob withheld a lot of information from Richard during this time, including any information about his candidates, and when Jacob died, Richard lost all faith in him.
