MONKEY ISLAND SERIES SPOILERS

Since ‘Escape from Monkey Island’ seemingly retconned the history of Herman Toothrot many have been confused as to how he could be one and the same as Elaines grandfather Horatio Torquemada Marley.
Fortunately, it can be simply explained, especially seeing as Herman has had several cases of memory loss.
See here for the spoiler full story:
The life of H. T. Marley
20 years before Guybrush Threepwood arrived on Mêlée Island, Pirate Captain Horatio Torquemada Marley was Governor of the Tri-Island area.
The tale of his transformation began when he sailed off on board his ship ‘The Elaine’ with his crew, Rum Rogers Sr., Young Lindy and Rapp Scallion the cook, to find the Legendary Treasure of Big Whoop.
They stopped to stock up on supplies at Blood Island. While there they met the pirate LeChuck (who was alive at the time). One night LeChuck got talking to Rogers in the Goodsoup bar. Rogers having had a few too many drinks blabbed about what they were doing and LeChuck took an interest. He got Rogers even more drunk and stole the map to Big Whoop, then made himself a copy before returning the original. It became a race to the treasure.
LeChuck got to Dinky Island first, shortly followed by the crew half an hour later. They found out that Big Whoop was actually a gateway to hell. Whoever passed through it would gain incredible power, but would also become undead. LeChuck used it and became an immortal ghost.
The crew witnessed this and were horrified. They promised to never let the secret out. First they buried a fake treasure that any later explorers that got this far would believe was Big Whoop. Then they split their map into four pieces and took one each. The crew returned to their respective homes and Marley returned to Mêlée Island. They began spreading rumours such as that the treasure could be found on Inky Island and so on, to throw people off the trail.
LeChuck wanting to ensure the location of Big Whoop was kept a secret known only to him vowed to kill each member of Marleys crew.

LeChuck kept his promise as best he could. Rapp died in a fire in his Weenie Hut on Scabb Island, Young Lindy committed suicide after going broke on Booty Island and Rum died in an accident involving a toaster and his bath in his home on Phatt Island.
Some time after this Marley sailed to Australia to get away from the life of Governor of the Tri-Island area. While there he met Ozzie Mandrill. In a boat race they had been preparing for, Mandrill rammed him into a freak whirlpool. LeChuck took credit for this as everyone thought Marley had been killed.
However Marley had washed up shipwrecked on Mêlée Island and the shock of this freak incident had made him lose a lot of his memory. Seeing the initials H.T. on his accordion, he assumed the name Herman Toothrot.
Later on that year, he became first mate under an unknown pirate on a ship called the Sea Monkey. They sailed out together to find the legendary Monkey Island.
While preparing a meal, Toothrot came across the Voodoo spell needed to find the Island. The two pirates sailed their rowboat out to shore and explored.
When the Captain hung himself, Toothrot knew he could not get back alone. He trained some monkeys to sail the ship to Mêlée and find help. When they got there Stan claimed the ship unknowingly leaving Toothrot stranded on Monkey Island until Guybrush Threepwood arrived.
Threepwood took H.T. back to Mêlée Island, then went away to battle LeChuck. Meanwhile Toothrot discovered the tunnel in the alley behind the church that led to Dinky Island, the home of Big Whoop.
While living as a hermit there he became a philosopher and taught who ever came by. Threepwood a year later found him again while searching for Big Whoop. While Threepwood fought LeChuck once more, Toothrot must have gone back to Mêlée Island. From there he sailed his ship to Monkey Island again. He made a good home on the beach out of his ship (he felt that to be a good hermit, you could not own a ship). He built a mine in the canyon for gold.
One day while mining in his cart, he had an accident. This knocked his memory out completely. Threepwood came to the Island again and found Toothrot in a daze. He threw various objects at him, each one knocking some memory back into his mind.

Eventually, Marley/Toothrot remembered his true identity and that he was Elaine Marleys grandfather. Now he had to rescue his granddaughter from LeChuck with a bit of help from Threepwood.
They unleashed the Secret of Monkey Island (a giant Monkey Robot/ Ultimate Insult) along with Jojo Jr., the monkey prince. They used it to defeat LeChuck and Ozzie Mandrill. Once LeChuck and Mandrill had been killed, Horatio Marley became Governor of the Tri-Island area again.
















