He was once an adventurer working as a knight of the Order of the Golden Cup and tithed 50% of his gains to the organization. Despite this, he became a very wealthy man and established a comfortable homestead on a large estate in the northern part of Damara.
The war with the Witch King Zhengyi and the army of Vaasa tore apart Gareth's comfortable life. He commanded a brigade of Damarans in the war and achieved every single objective he was tasked with. In retaliation, the Witch King burned down his estate. With his home gone and his men either dead or dispersed, Gareth traveled to the southern baronies of Damara, left as vassal states by the victorious Zhengyi.
He was recruited along with six other adventurers, Olwen Forest-Friend, Friar Dugald, Riordan Parnell, Celedon Kierney, Emelyn the Gray and Kane to protect the village of Bloodstone from an army of bandits. After a difficult battle, the heroes prevailed and were next sent to investigate the recently abandoned Bloodstone mines after a series of vicious Worg attacks. In the mines, he and the party discovered a temple to Orcus. The Duergar of the temple were planning on gating in Orcus to the Material plane but Gareth and his party foiled the plot by killing the Duergar clerics performing the ritual. Gareth then helped set up a mining agreement with the Svirfneblin living in the mines that ensured increased prosperity for the Barony of Bloodstone.
During these adventures, Dragonsbane had fallen in love with the Druidess Christine, daughter of Baron Tranth of Bloodstone and the couple had been engaged to be married. The wedding was held in the Spring of the next year. During the wedding feast, Baron Tranth surprised everyone by stepping down as Baron and placing the title in the hands of his new son-in-law, making Gareth the sixth baron of Bloodstone.
With Bloodstone now prosperous with the reopening of the mines, the town flourished, but then an assassination attempt on Gareth and the other adventurers now on the council of Bloodstone roused them into action once again. Following leads, Tranth suspected that the attack was from the Duchy of Arcata, a theory proved when Arcata marched against Bloodstone soon afterwards. It was the start of a second war. Arcata was added to the Bloodstone territory after a lightning counter attack on the city of Valls. With Arcata defeated, the Duchy of Carmathan joined the fray but were defeated as well. With this news, the Vaasan puppet baronies of Ostel, Morov and Polten attacked but lost to the armies of Bloodstone too. The territories of Damara had finally been united. The Grandfather of Assassins, a close ally of Zhengyi, lured Gareth and his party to his mountain stronghold, which could not possibly be taken by sheer force. Brilliantly though, Gareth led his original party into the fortress disguised as assassins themselves and succeeded in neutralizing their threat. Unfortunately, this was the last straw for Zhengyi who amassed the armies of Vaasa to put down the impudent ones to the south.
The battle was held at Goliad, the scene of the greatest defeat for Damara in the first war with Vaasa, this time though, the Damaran army battled to a stalemate after it was realized that Zhengyi's undead troops could not move south of a certain line on the battlefield as it was too far from the magic that animated them in Vaasa. The mortal warriors were defeated and the Damaran army left the field of battle for Heliogabalus where Gareth was soon crowned king of all Damara.
There was still an undead army waiting at the northern border and the Witch King was still alive to threaten the new kingdom though. Attacking Vaasa head-on would be suicidal, even if the armies they had at their disposal had not already been weakened in the battles of the past months. It was up to Gareth's party once again to save the day. The party traveled to Castle Perilous where they defeated the demons and dragons that defended the place to reach Zhengyi himself. It was an epic battle, and Zhengyi was finally killed.
Before his death, Zhengyi had teleported to another part of the castle where he defended a portal to the Abyss with the last vestiges of his unlife. Saint Sollars, the patron saint of Bloodstone Pass appeared to the party and informed them that Bahamut wanted to prevent Orcus - Zhengyi's patron - from getting to the Material Plane. They were tasked with traveling through the Abyss to the realm of Orcus where they would steal his famed wand and deliver it to him in the Celestial planes. Traveling through dozens of Abyssal layers, they finally made their way to Thanatos where they snuck into The demon lord's castle and, utilizing a pre-organized distraction that lured Orcus away, stole the wand and fled to the Astral Plane where they were escorted by archons to Saint Sollars. Told that only Bahamut could destroy the artifact, the party went to him who then told them to steep it in the blood of Tiamat's heart. He transported them to where an avatar of Tiamat lay in wait and was thusly killed. The wand was destroyed, leaving behind a gem, then they were returned to Bahamut who told Gareth to plant the gem in his castle's courtyard. They were then returned to the Material Plane victorious.
Zhengyi's undead crumbled without the wand of Orcus, leaving only the surviving monstrous elements of his armies, who had fled into various hiding places in Vaasa. The gem was planted and within two weeks it had sprouted into a 10-foot tall white tree with golden leaves. But, the adventure and war was now over and Gareth has ruled benevolently with his wife ever since.
Notable events in his life since the war included his interactions with the mercenaries Jarlaxle and Artemis Entreri after their defeat of the Zhengyian construct and the subsequent capture and interrogation of Entreri, with whom he argued about his own benevolence and, moved by Entreri's logic, vowed to make himself more worthy of his position as king and in turn granted clemency to the pair and their new associate, Athrogate by banishing them from Damara, rather than executing them, against the wishes of Christine and his friends. In 1373 DR his soul was transported to the Plane of Shadow by a cabal of wizards working for Sammaster which left Damara vulnerable to the attacks of the more organized elements of Vaasa's remaining monsters who swarmed down from the north as soon as they had heard the news. Gareth was quickly rescued from his fate by a pair of dragonslayers and once recovered, collaborated with an ancient vampire dragon named Capnolithyl to conjure an illusion of Zhengyi riding on the dragon's back to give hope to the enemy, making them think that he'd returned from the dead somehow. Gareth then quickly 'slew' the illusion, completely demoralizing the enemy and leading to an easy victory.
- Crusader the Holy Avenger is Gareth's magical longsword. The sword is blessed by Ilmater and Gareth aquired it while he was still an adventuring knight. Gareth used it throughout his time in the Cold Lands and held onto if for the rest of his days. A powerful weapon in its own right, as he grew in power, so did it, and as well as the powers of dispelling magic and doing extra damage to evil creatures it also healed the injured of all their wounds, both physical and otherwise, increased the users strength and could charm people when Gareth's own personal charm wasn't quite enough. It also had the power to disintegrate the weaker denizens of the Lower Planes.
- The Silver Horn of Valhalla summoned several barbarians from their afterlife in Warrior's Rest to aid Gareth in battle.
- Douglas Niles and Michael Dobson (1985). Bloodstone Pass. (TSR, Inc). ISBN 978-0394548562.
- Douglas Niles and Michael Dobson (1986). The Mines of Bloodstone. (TSR, Inc). ISBN 0-8803-8312-7.
- Douglas Niles and Michael Dobson (1987). The Bloodstone Wars. (TSR, Inc). ISBN 0-8803-8398-4.
- Douglas Niles and Michael Dobson (1988). The Throne of Bloodstone. (TSR, Inc). ISBN 0-8803-8560-X.
- R.A. Salvatore (July 2007). Road of the Patriarch (Mass Market Paperback). (Wizards of the Coast). ISBN 978-0-7869-4277-0.