Born a common farmer, the man who would become one of the Empire's most wanted men started his career as a revolutionary leader, sparking the 3A Moín Uprising after famine killed his family and House Murcadha did nothing to help the common people. Logan Unknown slew several members of the Murcadha family, including the incumbent Baron, his wife and his two eldest sons, leaving only the youngest son (Lucan III Murcadha), his infant sister (Liana Murcadha), and the Baron's elderly mother alive.
Logan eventually came to the conclusion after a blood loss induced hallucination that Leannan (a famously peaceful and generally pacifistic Goddess) wished for him to act as judge, jury and potentially executioner to the rich so that only those who truly deserved the power in their hands would have it. His increasingly deranged anarchist viewpoint quickly caused the followers he gained during the Uprising to leave him as he rapidly lost sight of the original reason he began the rebellion. Thus, he travelled the North of the Grand Duchy of Tir alone for several decades, testing the nobles of the Duchy based on a test of his own concoction and then, if they failed his test, he would challenge them to a duel to the death. It is noted that in this manner he killed at least eight other nobles, whose helmets he attached to his necklace as trophies, as well as killing a number of other people for various petty infractions.
It is also noted that not one person passed his test, as the criteria were fundamentally impossible - this has been analysed by many who wish to study his mental condition, and many now come to the conclusion that he was schizophrenic and suffered from severe delusions of grandeur. It is thought he saw himself as an arbiter for Leannan's will. His test consisted of asking if the person in question felt they earned or deserved the power they had over the lives of their subjects, and why do they have the position that they hold (it is noted that these two questions are inherently contradictory considering he asked both questions exclusively to nobles of privileged families who inherited their titles.)
His end came in 3A 198 following a duel with Balor V Drakenfiend, where the knight (who was barely even an adult at this point) found him with the intention of fighting and killing him. After ignoring Logan's usual bombardment of barely-coherent questioning, the two fought and Logan was injured but tore the young man apart with ease using his bare hands and attached his helmet to the necklace. Orla Drakenfiend was enraged at the death of her nephew and sought out Logan herself afterwards, and after interrupting his questions and explaining her reason for being there killed the notorious bandit, who was still recovering from the duel with Balor, in two strokes without him even touching her, disembowelling Logan and then decapitating him as he fell to the ground.
His body was incinerated and his ashes dumped in the moat of Castle Drakenfiend, and his head was brought back by Viore and stuck on a pike above the castle gate; his skull now sits in the crypt underneath the castle, hanging over the entrance. His sword now resides in the Drakenfiend armoury.
Following his death, Logan Campbell has become something of a rallying figure for anti-Imperial separatists such as Oglaigh na Tír, who view him as a martyr for their cause. The vast majority of Imperial and, indeed, Tiran citizens view him as a serial killer, and that his only real contributions to history are the destruction of the original Moín Castle and being part of House Drakenfiend's long list of noble deeds.