Loren Lannister was born the second son of Lord Gerion Lannister and Lady Rhya Lannister. His elder brother, Tyrius Lannister, was heir to Casterly Rock and from an early age Loren's feelings of inadequacy drove him to feverish performances in his lessons, both in swordplay and in lordly matters. Blood, however, is precious to the Lannisters, and despite their frequent bouts Loren and Tyrius were close, learning the ways of war and rule together until their father’s death. Loren served as his brother’s right hand man until Tyrius’s death during the second Greyjoy rebellion, where, while fighting alongside King Renly Baratheon at the battle of Pyke, Tyrius received an axe wound to the arm, bleeding out in a matter of minutes. Loren had urged his brother to take no part in the bloody conflict and was quick to place the blame for his death upon the Baratheons who had called House Lannister to war.
Soon after the conflict's end, the new Lord of Casterly Rock wed Gwynesse Greyjoy, an ironborn woman of House Greyjoy. Some whispered that the marriage was an act of spite, others said a calculating seize for power. Lord Loren himself proclaimed it to be an act of love, and the birth of his heir, Damon Lannister, soon afterwards seemed to validate those claims (though it was later learned that Damon was the son of Tyrius Lannister, as he and Gwynesse had fallen for each other and wed near the beginning of the rebellion). King Harys Baratheon, although unhappy with the marriage, granted Lord Loren the title of Warden of the West, partially in hopes of culling a future uprising from Lannisters and Greyjoys alike, but also in recognition of Tyrius Lannister’s significant role in the war. Loren's wife died some years later while giving birth to Ashara Lannister.
Early on in the first era, Loren sailed south to participate in the council at Bloodstone, a meeting held by Varyo Velaryon in order to gather support for Aerion Blackfyre's claim to the Iron Throne. While there, he and the Velaryon hatched a plot in secret to overthrow the Baratheon King and place Loren's own son Damon Lannister on the throne. The Blackfyre, unaware of these plans, returned to Casterly Rock with Loren where he was quickly married in secret to Ashara Lannister.
Soon afterwards, Loren sent a raven to Damon Lannister ordering him to return to Casterly Rock. When he arrived, the heir of the Lannister House was quickly married to Aeslyn Targaryen despite Damon's reservations about the arrangement. With the two weddings completed and thousands of soldiers already on the march from Lannisport, Loren sent Damon to lead the Lannister forces through the gates of King's Landing, leading him to believe, falsely, that it would be Aerion Blackfyre who was to sit the throne.
With Harys and all his forces in the south and an Estermont relative inside the keep, the sack was devastating, and the capital was soon under Lannister control. The Blackfyre was killed only a few moments after taking the throne, earning him the name "The Two Minute King," and Damon Lannister was placed on the iron seat in his stead despite his wishes to the contrary.
Loren Lannister was made Hand of the King.
Many bent the knee to the usurper, and during the battle of the Kingswood Harys Baratheon was slain by Damon Lannister, ending the first era.
After the fall of the late King Harys, it was decided that Damon Lannister would go south in order to solidify relations with Dorne, who had not stirred during the conflict. Loren Lannister was to go to Casterly Rock.
While there Loren retrieved the sword Widow's Wail, a Valyrian steel blade passed down from father to son for generations, with the intent of giving it to Thaddius Lannister. However, on his return trip east he received news of his son's (alleged) death along the Kingsroad at the hands of sigiless archers, along with the news of Aeslyn Targaryen's trial. His son's death prompted a period of deep grief, resulting in the hanging of many sigiless men along the Gold Road.
Upon his arrival at King's Landing, Loren began a systematic witch hunt for anyone involved even slightly with his son's death and the trial of the queen. One of the men who he questioned was Laenor Velaryon, who lost both an eye and an ear before being sent north to the Wall. Others involved, including Varyo Velaryon, fled across the Narrow Sea rather than face the Hand's wrath.
Eventually whispers reached the Red Keep claiming that Thaddius was not dead, but was instead disguised as a Reed in Winterfell and the lover of Jojen Stark, the Lord of Winterfell. Loren refused to hear such rumors and even went so far as to say "Better dead than [this.]"
The ancestral sword of House Lannister was later passed on to Damon Lannister as Loren believed Thaddius to either be dead or unworthy.
Soon after this, when the presence of bandits in the Riverlands was made known to the crown, Loren was put in charge of dealing with the Burning Hand's Men, a group which the crown falsely assumed to hold connections to the rising R'hllor movement. Loren placed Lord Arthur Swyft and Ser Osten Prester of Feastfires in charge of the task.
When Alannys Greyjoy visited King's Landing it was discovered that the Ironborn reavings along the western shoreline were in fact a collaboration between Lord Loren and Lady Alannys intent on weakening the north.
"If I cared for adoration I would feed the smallfolk, Lord Rymar. Perhaps I would do the same if I cared for the memories of fools."
"Do I look to be the sort of man who exchanges quips."
"A rich man with Kingly puppets and a fondness for cruelty." - Varyo Velaryon
“He is slightly warmer than a White Walker's grip.” – Damon Lannister
“You wouldn't know it, but Loren wasn’t always so sour. We used to play together as children. We chased each other all about the Rock and he would always let me catch him. We skipped stones across the fountains in the Stone Garden, we caught lantern bugs beneath the weirwood. It was Loren who came to me when our father declared that I would wed Aemon Estermont, a man twice my age from some small and miserable island I’d never been to. It was he who comforted me and told me that everything would be fine, that family was everything and that he would look out for me. And he did." - Jeyne Lannister
"After Lord Damron Greyjoy was slain and his house bent the knee once more, Loren married the man’s sister. An act of spite, Varus was sure of it." - Ser Varus
"Feasts are for those with little to do and less between their ears." - Loren Lannister to Damon Lannister
"Maybe he was too harsh with you. Maybe he was too critical. You certainly did your part in giving him plenty to criticize, but your father loved you very much. You're a fool if you think otherwise. Look at everything he's given you." - Jeyne Lannister to Damon Lannister
“Your counsel is important to me. I trust in you, and in your judgment, and I believe that you among all others know what is best… And not because I fear you, like everyone else. They take your advice because they are afraid of what would happen if they didn't, but that's not why I do what you ask me to. I do it because I believe that you're right." – Damon Lannister
"Loren Lannister spoke in tones icier than the north." - Blood and Whispers
What kind of Westerman takes a pirate into his bed? What kind of lord? What kind of Lion? - Symon Farman
"The heir to Casterly Rock had spent his entire life clamoring for his father's approval, but Loren had only ever offered criticism." - Blood and Whispers
"Loren was always skilled at getting others to fear him, but it takes something greater than that to make people love you." - Jeyne Lannister
"But if there was one man that could scare the Stranger into submission, it had been Loren Lannister ... He and Loren had never had a comfortable relationship, but he supposed no one had that with the man." - thoughts of Nathaniel Arryn
"My father used to say that when it came to crutches, men with weak bodies used canes and those with weak hearts used wine. He never partook… They tell me it was his heart that killed him, but perhaps his quip was not meant to be literal. He had plenty of others, one for each and every shortcoming of mine.” – Damon Lannister
"What is it about losing a brother that seems to turn you all to stone? You were not close with Thaddius. Not as Loren was to Tyrius. Thick as thieves, those two... Most of the time..." - Jeyne Estermont to Ashara Lannister
"He was a serious boy, true, but Tyrius wasn't and someone had to be." - Jeyne Estermont
Gerion Lannister, father (deceased)
Rhya Lannister, mother (decease)
Tyrius Lannister, brother (deceased)
Jeyne Lannister, sister
Gwynesse Lannister, wife (deceased)
Damon Lannister, nephew/adopted son
Thaddius Lannister, son (deceased)
Ashara Lannister, daughter