Prior to the events of Shadow Dragon, Ogma was a gladiator who fought in an arena in Archanea. One day, he led an uprising against the owner of the arena, and allowed all the other gladiators to escape slavery, while he remained to distract the guards. After he was subdued, he taken to the town square and beaten in public. Princess Caeda and her father King Mostyn were visiting from Talys as this happened, and Caeda begged for her father to save the abused gladiator. After paying a small fortune to the arena, Ogma was a free man, but decided to dedicate his life to protecting Caeda and her father.
When Prince Marth and the Altean Knights left Talys for Archanea, King Mostyn ordered Ogma and his men to accompany Marth and Caeda. At the port town Galder, Ogma met up Marth and warned him of the approaching Grustian cavalry. Together, Ogma and the knights defeated the cavalry and the local Galder Pirates, Ogma continued to serve Marth well, and accompanied him to the final fight against Emperor Medeus. After the war ended, Ogma returned to Talys and resumed his duty as leader of the Talys Mercenary Knights.
By the Sword
After it was announced that Prince Marth and Princess Caede were to be wed, all the local tribes who opposed King Mostyn led a rebellion. In this war, Princess Caeda went missing, and Ogma ordered to find her and defeat the rebels. As he engaged the enemy, he noticed that his rival Navarre was among the enemy army, and he retreated to a safe distance. As he retreated he met the wandering mercenary Maris, and her father Dice among the enemy and he figured he was at his end.
This was not the case however, Maris and Dice were saved by Ogma years ago, and when they saw their savior in trouble, they switched sides instantly. As they fought, Caeda and the Altean archer Norne arrived, and Caeda convinced Navarre to switch sides, as she did during the war. Together, the warriors defeated the rebels and peace returned to Talys.
Mystery of the Emblem
When General Lorenz of Grust led an uprising against the cruel General Lang of Archanea, Mostyn ordered Ogma to help his friend Lorenz. When Ogma arrived in Grust, Lorenz was on the brink of death, and he asked Ogma to take Prince Yubello and Princess Yumina into safety. The siblings refused to leave Lorenz's side, so Ogma left to assassinate Lang.
When he heard that Lorenz had died, and the children were taken hostage by Lang, Ogma flew into a rage and rescued the children from Lang's castle. He took the children to Macedon to meet with Bishop Wendell, however they were surrounded by pirates. When all hope seemed lost, the wander Masked Knight Sirius appeared, and he helped Ogma save the children. With the children safe, Ogma joined Marth's army, and helped him defeat General Lang. When Altea was invaded by Emperor Hardin's Archanea, Ogma helped Marth fight the derranged emperor, and later battled Medeus once again.
Ogma jumpstarted an archetype of Mercenaries with slightly above average stat growth rates, making them fan favorites in their respective Fire Emblem games. He started the Hero class. Members of the Ogma archetype are: