Bremen grew up in the highlands south of the kingdom of Leah. His parents moved around too much, and therefore couldn't raise him properly, so they left him with his grandparents. Bremen later joined the Druid Order.
In the aftermath of the First War of the Races, the Druid Council chose to renounce the study of magic; but Bremen, who felt that magic could be controlled if studied carefully, continued its practice. As a result, he was banished from Paranor. After years of wandering the world, Bremen eventually discovered that Brona, the figure behind the war who was thought dead, was actually still alive and planning an attack on Paranor and the rest of the world. Bremen returned to the Druids to warn them, but aside from a few who believed him, the Council didn't listen (in no small part due to the fact that Athabasca, the Ard Rhys, hated Bremen). As a result, the Druids at Paranor were massacred with ease when the Warlock Lord attacked.
After his visit to Paranor, Bremen traveled with his companions to the Valley of Shale, and by summoning the dead Druid Galaphile out of the Hadeshorn he was shown what was needed to destroy the Warlock Lord. He also learned of the Black Elfstone, a magical weapon that would grant the Warlock Lord tremendous destructive power.
Bremen recovered the Eilt Druin from the tower of Paranor so he could use the amulet as a component in the Sword of Shannara to defeat the Warlock Lord. He received information on how to forge this mighty weapon from Cogline, an old friend, and had the sword made by an expert weaponsmith named Urprox Screl.
On the way to Arborlon, Bremen met Allanon as a small child in the burned city of Varfleet. Bremen chose Allanon as his Druid apprentice and taught him Druid magic, then gave the sword to Jerle Shannara, King of the Elves. Unfortunately, Jerle Shannara wielded the sword ineffectively on the Warlock Lord, leaving the task of finally eliminating the villain to his descendant, Shea Ohmsford.
After these events, Bremen spent the next few years training Allanon. Eventually, he realized that his time in this life had run out and went with Allanon to the Valley of Shale. He was taken into the Hadeshorn by Galaphile to be with the shades of other dead Druids.
Bremen's spirit continued to guide Allanon through his journeys. When Allanon died at the hands of a Jachyra, Bremen's spirit carried him to the afterlife, into the Hadeshorn.