What follows is a list of NPC write ups I've created for use in my Realms campaigns set in Cormyr.
Since I first started this project the list has grown beyond the bounds of my Realms games and taken on a life of its own.
I hope you find this list useful to your Realms game and/or an entertaining diversion for the time you spend reading the entries.
List of NPCs:
Daervin "the Bold Lion" Ambrival
Aurbrand "Firebrand" Ambrival
A tall, mustachioed man with curly, red hair worn long and unkempt, Aurbrand “Firebrand” Ambrival was a sellwsord, adventurer and later in life a noble of Cormyr.
Aurbrand was the leader of the Company of the Singing Harp, itself comprised of adventurers native to Cormyr, Westgate and various settlements along the Dragonmere. Initially numbering ten members, the Company of the Singing Harp was formed to find the famous (some would say infamous) Harp of Healing.[1]
The Company ranged far and wide in Cormyr and the lands bordering the Forest Kingdom for a decade and a half, finding much adventure, treasure and fame, but never did the Company of the Singing Harp discover the true whereabouts of the Harp of Healing.
Aurbrand stood half a head taller than most men and was always eager for battle. Though he fought often he was no mean killer, preferring to leave a man bruised and unconscious as opposed to dead and dying. He led the charge for every battle the Company of the Singing Harp fought and took much pleasure in swinging his broadsword two handed to cleave and slay orcs, magical beasts and worse.
Aurbrand earned a title of nobility from King Foril after the Company of the Singing Harp fought their way into a haunted keep north of Nesmyth (known to locals as Wizard's Run; so named for the swift flight on foot of the wizard Gardgragath the Unseen from his keep, but not before several animated suits of battle plate chased him down and slew him) and confronted an unknown power that was animating objects within the keep and sending them to slay any who approached too close to its walls.
The keep proved every bit as deadly as the rumors claimed: Aurbrand emerged alone from the keep, bloodied but not beaten, his longtime companions all having fallen.
The loss of his adventuring companions tempered Aurbrand’s battle lust. He settled in Wizard’s Run and refused to have his new grant of holdings and land be renamed, seeing it as a last gesture of respect to his fallen comrades.
Aurbrand is survived by two sons, the eldest Endeir and his younger brother Daervin. The death of his wife in childbirth broke Aurbrand’s heart and he did not remarry. Aurbrand chose to retire to Suzail when his eldest son came of age, thinking it best not to be a constant shadow over his son’s shoulder.
Aurbrand left the bulk of his fortune behind, keeping only a small sum with which he purchased a mansion in a quiet, out of the way part of Cormyr’s capital. Spry even in old age, Aurbrand spent his last years sallying forth in the evening from his home in the Windmarket district, walking the length of the Promenade and ending his trip at the Society of Stallwart adventurers, there to relive old times and tell the stories of his adventures with other retired, surviving members of (once rival) adventuring parties.
None can speak with certainty about when or how Aurbrand died, though word has circulated amongst the Society's elder members that Aurbrand was last seen by his servants: one night after a too-late visit to the Society's halls, Aurbrand was sighted at the just-opened gates to his home, looking upon the translucent form of a woman glowing within a nimbus of blue light. A magnificent golden harp appeared between them that when touched by Aurbrand caused both he and the strange apparition to vanish into the night.
[1]Those wishing to know more about the Harp of Healing need look no further than Dragon #280 and the article titled "The Adventures of Volo: Lost Treasures of Cormyr, Part 3" therein.
Information about Nesmyth can be found in Volo's Guide to Cormyr.
What little canon information (that I know of) about the Ambrival noble family can be found on page 94 of the novel "Bury Elminster Deep." If you know of any other sources that discuss the Ambrivals, please shoot me a PM. Thank you in advance. 
Endeir Ambrival
Word of the disappearance of Lord Aurbrand Ambrival took its time in reaching the ears of his eldest son and heir, Endeir.
While Crown investigators assisted by War Wizards busied themselves with determing the elder Ambrival's fate, Endeir sat at Wizard’s Run, thoroughly discontented with his father, his drunkard brother and the back country surroundings of his home.
Endeir’s father spared no expense educating his son, sending him to the best tutors and schools (“best” here meaning those places other established nobles sent their children) but rarely during this time was Endeir ever regarded by his peers as a true noble of the Forest Kingdom.
Endeir became fast friends with scions of other new blood noble families, but observed that where his compatriots were encouraged, cajoled, pushed and practically threatened by their mothers and fathers to make a name for themselves, increase their influence and establish a place in Cormyr for their hopefully long-lived noble lines. Endeir’s father seemed entirely unconcerned with such matters, preferring to make deals and then let the world around him conduct its own affairs.
Aurbrand’s retirement to Suzail was of little help to his eldest son. Though Endeir held a noble title and controlled the majority of his family’s wealth, he did not command the considerable measure of respect granted to his father by the merchants, farmers and commoners who lived and worked in nearby Nesmyth and the surrounding lands.
Endeir’s attempts to influence these individuals were, if not exactly rebuffed, politely deferred to a later time. He was often greeted with, “Whither Aurbrand?” before learning that his ideas, his advice and his coin, though appreciated, were not needed.
Without being told outright, Endeir sensed that so long as his father lived, he would be forever in his shadow. As well that the world beyond his castle walls seemed to care little that Endeir was of the nobility.
Endeir’s sense of frustration and resentment grew when word finally reached him that his father had disappeared. Despite being declared dead by the Crown, the lack of a “clean” death left Endeir fearing his father might any day return from some last, grand adventure and undo by his presence alone all the work Endeir had yet to undertake.
Suzail, the great capital of Cormyr, held opportunities that far away Nesmyth lacked. What was to be a short visit to settle his father's affairs turned into an extended stay. Endeir took up residence in his father’s mansion and made several forays into the city. There he discovered his coin was welcome, even desired, but powerful merchants, non-nobles all, held far more coin than Endeir and cared only to make him a junior partner in their endeavors.
Endeir also discovered no shortage of frustrated, angry-at-the-Crown nobles with whom he shared common cause. The ship of Cormyr was sailing in the wrong direction, of that there was no doubt. His peers saw the rise of the merchant class and the commoners as an affront to all nobility.
This frustration came to a head at the Council of the Dragon, called by King Foril to address the many concerns of the nobility, particularly with regard to the Suzail Writ. Endeir found himself happy to be embroiled in talk of justice, plots (against the Crown and fellow nobles), treason and discussions rife with bombast and rhetoric.
Endeir spent much of the family wealth bankrolling mercenaries, renting property for clandestine meetings and facilitating the work of many nobles to bring change to Cormyr, all on the promise that his efforts would be rewarded in a future Cormyr brought to heel by the nobility.
In all this Endeir felt he was doing something that finally mattered.
Endeir arrived at the Council of Dragons proud and confident. That pride proved short lived, as Endeir was the second of three nobles to be attacked and slain by a Blueflame ghost while the council was in session[1].
The mansion Endeir occupied was set afire and looted soon after his death. Though his few surviving friends claim rebellious servants were responsible, Endeir’s former servants tried to put out the fire before being set upon by unknown assailants and forced to flee the mansion. What little wealth Endeir kept, if any, was lost.
The mansion, called Ambrival House, stands to this day a blackened, scorched ruin of stone, waiting to be claimed by the next Ambrival in line.
[1] You can read the brief but gory details of the death of a Lord Ambrival on page 94 of the novel "Bury Elminster Deep". I gave this dead lord the name Endeir and made up this back story for him.
Daervin "the Bold Lion" Ambrival
Daervin “the Bold Lion” Ambrival is the patriarch of House Ambrival and thought to be the last of the Ambrival line after his elder brother Endeir was slain at the Council of the Dragon in Suzail.
Daervin stands six and one half feet tall, is broad of the shoulder and ties back his long, curly blond hair with a leather thong. In addition to a noble title, modest landholdings and wealth, Daervin inherited his father’s brash, bold manner and a lust for adventure.
Daervin’s father Aurbrand recognized the fire in his son and promised he would not be barred from seeking adventure, so long as he completed the same schooling as his elder brother.
This Daervin did, leaving Wizard’s Run with a would-be band of newly chartered adventurers when he’d reached his seventeenth year of age, eager to make his own fortune and a name for himself as the leader of a great adventuring band.
But unlike his father, Daervin’s adventures did not bring fame, riches or recognition by the Crown of Cormyr. Daervin experienced year after year of calamity, ill-luck and the death of close friends. Those few treasures the Company of the Bold Lion recovered were used to pay for magical healing and squandered on treasure maps and rumors of riches that proved to be either misleading or false.
Realizing that the career of adventurer was not something suited to the life of a noble, Daervin wed Challantha Rhondar, his longtime love and only surviving sword-comrade. The couple retired to the family estate at Wizard’s Run, hard by Nesmyth, in southeastern Cormyr.
The couple’s first and only child, Belmer, was born within a year. The family rejoiced at the birth of their son, but were saddened to learn their son was born blind. That same year a harsh Cormyrean winter brought with it an illness that Chalantha was ill suited to repel so soon after her pregnancy.
Daervin spent that last of his personal wealth seeking a cure for Chalantha’s malady, but no priest or wizard could aid her; they could only ease her pain.
Chalantha passed away within a year, having given all of her love and the last of her life’s energy to her only son.
Leaving Belmer in the care of his grandfather, Daervin left for Suzail soon after his wife’s death, hoping to lose his pain in the task of finding and courting a new wife amongst the nobility; one who would fall deeply in love with him and bear a healthy child not inflicted with his first son’s malady and thus capable of carrying on the family line.
Daervin returned home only a handful of times over the years, never having made any headway in his search for a bride, each time more haggard and more likely to bellow his cynical frustration at the arrogance of his fellow nobles and the “unfairness of it all.”
Daervin’s years in Suzail came to an end after his father arrived (the later having chosen Suzail as the place where he would retire) but not before Daervin had become deeply indebted to various creditors. Lord Ambrival banished his son from Suzail and ordered him to return to Wizard’s Run, but he did not relieve Daervin of his debts, exhorting him to find his own means to pay what he owed.
Daervin’s burden was not lifted after his father died. His elder brother Daervin, after becomoming head of the family, quickly severed Daervin’s access to the family wealth, leaving him practically a pauper in the family castle.
The death of his elder brother served to multiply Daervin's troubles. Agents and factors of various noble families and merchants, whether seeking repayment of loans or seeking commitments from Daervin to make good on his elder brother’s promises, are a frequent sight at Wizard’s Run, as are various Crown agents and officials, the later rumored to have questioned Daervin none too kindly about his elder brother’s treachery and the loyalty of the House of Ambrival to Cormyr.
Daervin's efforts to resume the business his elder brother let falter have produced little in the way of coin. He's overheard whispers and rumors claiming his is a cursed family (this he believes the more he drinks) and that the ghosts of Wizard's Run awaken in the night to watch his keep from a distance.
The young noble family of Ambrival stands precariously close to collapse. Word at court is Ambrival is up to its ears in debt and all but guilty of treason, its current patriarch is a sullen drunkard ill-suited to the task of leading a noble family.
Ambrival is expected to implode under the weight of its troubles within a year.
Challantha Rhondar
Challantha Rhondar was a dark haired, tawny skinned songstress hailing from Ordulin in Sembia who stands as tall as a man, with wide shoulders, deep chestnut brown hair and glittering brown eyes.
The daughter of an always for-hire wagon merchant, Challantha spent much of her life moving up and down Sembia’s coast, north into the Dales and on occasion west into self righteous, overly proud Cormyr, always traveling with her father as he delivered goods from the ports of Sembia to far off places.
It was on one such occasion that Challantha happened upon a lanky, bumbling youth, all hands, feet, bright white teeth and honey blond hair, named Daervin Ambrival.
Though she was no longer a girl at the time, she was not nearly a woman. Challantha was warned to stay close to her father, but she rebelled against his stern warnings, accompanying the bright eyed young noble the next day as he went about his business, while her father spent most of his day looking up and down Marsember for her.
Daervin was in the habit of tying his hair back before engaging in sword practice, on the advice of his sword masters that untied hair was a liability in battle, so she taunted him, asking if he always did as he was told. She encouraged him to let his hair run wild, saying, “Go forth, my bold lion, to strike down your foes and win the battle this day.”
Challantha would compose on the spot ballads of his exploits: songs of folly if he did poorly, songs of valor and bravery if he faired well against his teachers.
She was reluctant to part with the young lordling that’d so caught her eye, Challantha returned to her frantic father that night and left for Sembia the following morning.
Being expected to remain silent at her father’s side taught Challantha the art of listening. After conducing his business, her father would quiz her about the conversations going on around them both while he was dealing with customers. Challantha marveled at her father’s ability to listen to what was going on around him while haggling loudly or arguing fiercely in a hushed voice, as the situation demanded.
She learned well the art of observation and listening.
Her father wished her to learn bookkeeping and the life of the merchant, but the songs of bards and minstrels, the mournful ballads of elves leaving the forest, bawdy pirate songs popular in seaside taverns up and down Sembia’s coast, the chants of the many faiths of the Realms and the hearth songs mothers sing to their children in the Dalelands called out to Challantha more.
She took up the harp as well as the lute early on, spending her time plucking away until she could replicate the tunes she’d heard on the road. In this way she learned to sing as well. By the time she was fully-grown she could sing and perform as well as most house bards in any average inn or tavern in Sembia.
Challantha never told her father about her magic; how she could make objects dance to the tune of her song, how she could light candles from a distance, cause clay pots to shatter with a sharp note, make a man's heart race with a lusty song or their blood boil with a ballad of treachery, and warm blankets or whole rooms with songs of comfort, joy and family.
On his deathbed she left her father smiling and content, singing him to sleep one last time as age and infirmity took him away from her forever. What little was left of her father’s business she sold for less than it was worth, taking the coin and a single horse-drawn wagon with which she departed for Cormyr.
By chance or by fate she met the not so young lord Ambrival as he was preparing to depart Nesmyth for a life of adventure. She joined with Daervin and his companions, the six of them forming the Company of the Bold Lion.