In Curse Of Strahd, Godfrey met Ezmerelda D'Avenir, who he found while she was staking out Argynvostholt. He beseeched Ezmerelda to speak to Vladimir, and the Vistana complied; during the conversation, she wished to take the Captain's Holy Symbol of Ravenkind, and Vladimir quickly rose and summoned Phantom Warriors to kill the woman. However, as they slew her, Godfrey intervened, and secretly cast a spell on Ezmerelda to stave off her death. He took her to the top of the tower at Argynovsholt and warded her body, though eventually lost his memories of her and again began to roam the Svalich Woods.
Born to a wealthy family who lived in a mansion near the border of Fort Verdane, Godfrey Gwilym was set to live a luxurious life. However, he found his days in the manse quite boring, and found more interest in swordplay; able to hire skilled tutors, he became a fine swordsman himself. One day, he overheard of a secret group of paladins that met in Emblem. His desire for adventure took over his want for a nobleman's life, and he traveled to the capital, and eventually became a knight of the Order of the Silver Dragon.
After swearing his oath, Godfrey found that he excelled in divine Spellcraft, an uncommon but useful skill for a paladin. He was relocated to the Silver Dragon's Hideout, where he met the imposing and respected Vladimir Horngaard. Though of extremely different backgrounds, the two men found that the balanced out the others foibles, and they quickly fell in love. Alongside Vladimir, he battled for the forces of light against the myriad threats of the Underdark; during a defense of the hideout, he became good friends with the Dark Gnome Irsel Rill Lakerun Gembop Geoheart, as described in Captain Horngaard's Journal. Vladimir was eventually promoted to the role of Captain, with Godfrey his steward gaining the title of Sir Gwilym.
Argynvost's true purpose for the Order, hidden from its members, was to investigate the Azure Paragon and find out its secrets. This search led him to the Zarovich Valley, where a warlord named Strahd von Zarovich had begun terrorizing the region. He elected to defend its innocents against the would-be tyrant, and brought Vladimir along to construct Argynvostholt, a fortified mansion in the heart of the valley. Godfrey refused to part with his lover, as described in Godfrey's Journal, and the two found themselves fighting Strahd's armies time and time again as they swept across the land of Barovia. The knights experienced many early successes, notably in the Rout Of Barovia where Horngaard slayed Barov von Zarovich and Ravenovia van Roeyen, but these victories dwindled over time.
After the Wedding That Never Was, it became clear that Strahd could not be stopped, the knights of the Order led hundreds of refugees to Argynovst's valley, but Strahd tracked them to their sanctuary and overwhelmed them in the Attack On Argynvostholt. Godfrey bravely met Strahd at the gates of Argynvostholt, and was killed by the Vampire in single combat. With the battle won, Strahd surrounded Argynvostholt, and his forces eventually dragged down and killed Vladimir. Rather than cower in his lair, Argynvost emerged and battled Strahd's armies to the bitter end.
Unwilling to accept his failure, Vladimir returned as a Revenant. So great was his hatred of Strahd and his thirst for vengeance that those feelings fueled the spirit of Godfrey to do the same, as did many of his fellow knights. Godfrey accompanied Vladimir as he continued to wage a hopeless war even as Strahd tightened his grip on the valley, and was continually rebuffed with little effort. Due to the Count's pact with the Dark Power Vampyr, the knights spirits were trapped behind curtains of mist. Over centuries, the knights became hate-filled shells of their former selves, and Vladimir even began to forget his memory of Godfey.
Sir Gwilym, however, did not completely degrade as his peers had. Though consumed by hate and grief, he remembered both his love for Vladimir as well as his oath; when the rest of the revenants stayed in Argynvostholt, Godfrey roamed the Svalich Woods, killing those who bore the Mark of Strahd. He sought the aid of Barovians and foreign adventurers alike in his quest; he was sure that if Vladimir's hope could be restored, he would absolve the revenants of their vows and allow them to rest.