Romulus Hagrid had a difficult choice in front of him. His wife, Fridwulfa, had just left him with two children. And Rubeus and Fezzik were no ordinary children. Their mother was a giantess, so even as babies, the two were the size of small boulders.
But now….well, Romulus wouldn't try and kid himself that he could take care of both. He had to put one child up for adoption.
Sighing, he put an advertisement in the Daily Prophet, the Quibbler, Witch Weekly, and the Daily Muggle News Posting Wizarding Link. He would choose to give up Fezzik, because he believed Rubeus had more of a potential for magic. His sons' strength would already be a problem for a new family to cope with, he'd rather not surprise them with magic as well.
He knew that Dippet supported this choice. Dippet knew that he had had an affair with Fridwulfa, and he had even recommended giving one child up for adoption. So it was with a heavy heart that Romulus met with the Turkish family who came to see about Fezzik. They seemed like a perfectly nice couple, it was just that he loved his sons so much.
"Promise that you'll take good care of him, and that maybe I can meet him one day when he's older, when he understands?"
In time, Romulus and Rubeus learned to live as a two-person family. Romulus never told Rubeus or anyone else that he had had a second son. Romulus was overjoyed when Remus got his Hogwarts letter, but upset to learn that the Slytherin Prefect was a bully named Tom Riddle, who would often physically hurt his son. Luckily, Rubeus was in Gryffindor and didn't have to deal with Tom too much.
Meanwhile, Fezzik hated that his parents trained him to fight because of his strengths. When both boys were twelve, tragedy struck. Romulus and Fezzik's parents were both involved in tragic accidents. Neither survived.
When the boys were thirteen, tragedy struck again. Rubeus was expelled from Hogwarts, and Fezzik was forced back into fighting, and he accidentally killed a man of power. Then, he fled to Greenland. This was the closest the brothers had been since Romulus had given them up, but they had no idea.
Olympe Maxime was born to the giantess Mullafla and the wizard Alexandre Beaumont. Mullafla also abandoned them, but Olympe lived a good life. She was accepted to Beauxbatons Academy and later became the youngest headmistress the school had seen. Olympe was able to travel a lot, and she hoped to one day explore all of Europe. And that was how she met Fezzik.
I have way too many Harry Potter crossovers, and I know that. So I'm sorry if you were expecting something else. Except, not really sorry. Actually, not at all. Anyway, this is for all of the Princess Bride fans out there.