Sir Arthur Pendragon's Adventures
Sir Arthur Pendragon's Arrival
Seeking adventure and a place where he does not have to do the dirty work of the British Empire, the gallant Sir Arthur Pendragon followed a lead to a cursed ship named the Blackwyche.
Upon freeing the Blackwyche's crew from a terrible curse he is gifted the ship and told of the Sea of Thieves. He is also told by the now ex-Captain of the Blackwyche, Richard Cavendish, to seek out his daughter – Ana Cavendish — who is still in the Sea of Thieves.
Source
Sea of Thieves #2: Champions of Souls
Champion of Souls
In exchange for his service to the Order of Souls, Madame Olivia gifts Pendragon with the uniquely enchanted Sword of Souls. Using this Sword of Souls, Pendragon can free souls that are trapped or bound.
The Ferryman and Pendragon Meet
On a mission to rescue some lost souls, Pendragon dove too deep in search of a cave near Keelhaul Fort unfortunately drowning in the process. He appeared on the Ferry of the Damned where The Ferryman takes interest in the Sword of Souls that Pendragon holds and tasks him with finding a Lantern similar to the one he owns.
Pendragon returns to the land of the living and swiftly finds the Lantern. Back aboard the Ferry of the Damned, he dipped the Lantern in the Well of Fates and created a Lantern that could see lost souls on the Sea of Thieves.
Source
Sea of Thieves #2: Champions of Souls
Trapped By Graymarrow
Pendragon's last charge was to find and vanquish Lord Graymarrow, however in a turn of events he found himself at the mercy of this merciless Skeleton Lord.
Shipwrecked on Shipwreck Bay, Pendragon lay trapped beneath a mast as Lord Graymarrow took his Sword of Souls and learnt of how to bind souls by studying the sword. Graymarrow then sealed away Pendragon in a portrait of himself in the Captain's Quarters of the shipwrecked Blackwyche.