Although he may be an adoptive son,
To Fergus, Claire is the closest to a mother he's ever known. And for Claire, she loves and views Fergus as her child, whether she bore him or not.
In the 18th century, Claire winds up married to James Alexander Malcolm MacKenzie Fraser, of Clan Fraser of Lovat. They have several children: Faith, who doesn't survive birth; an adopted son named Fergus; and a daughter, Brianna.
Henri-Christian is born as the fourth child of Fergus and Marsali. He is a dwarf and some of the residents of Fraser's Ridge believe he is a punishment for his parents' sins. Henri-Christian is placed in a basket and put into a stream by some boys. Roger saves him and baptized him.
Well, Fergus is believed to be the son of the comte and Amelie Beauchamp.
In early 1779, pregnant Marsali, Fergus and their daughters Joan and Félicité settle in Wilmington. Their eldest son, Germain, returns to Fraser's Ridge with his grandparents, Jamie and Claire, as Fergus and Marsali think that it is dangerous for a boy Germain's age to live in a large city in time of war.
We do get to see a conversation between the two of them play out, with Marsali explaining that Fergus is being rough at times and leaves marks but that he isn't abusive.
Marsali however took to each trial courageously and saw a future away from Fraser's Ridge. In the fifth episode, she decided it was best to move her family to New Bern for a fresh start and to keep Fergus far from its negativity.
He is a 30-year-old handsome, savvy, charming man, still completely devoted to Milord and Jamie's most trusted man. He has a dangerous edge as well when needed and works with Jamie in his smuggling enterprise. We see this adult version of Fergus at the same time a newly returned Claire does. He can't believe his eyes.
Surprise! Jamie also has two step-daughters, Marsali MacKimmie Fraser and Joan MacKimmie. They became his step-daughters when he married their mother, Laoghaire MacKenzie. If that name sounds familiar, it's because Laoghaire is the same woman who orchestrates Claire being put on trial for witchcraft.
Fergus apparently knows Claire is a time traveler in Outlander. Diana Gabaldon mentions now and then on social media that Fergus knows Claire is a time traveler. This is something that happens off-book in the series. Fergus and Marsali have both learned the truth, which is important for later books.
Fergus is 17 years older than Ian and 15 years older than Marsali.
There wasn't a big goodbye post on social media to indicate that he was leaving for good. There are ways to bring Fergus back into it. In the books, he does remain part of the story. We check in with him and his family now and then, first in New Bern and then in other parts of the country they head to.
Fergus, known as Claudel in France, steals for Jamie, and Jamie makes a promise that he will always look after Fergus should he be arrested and lose a hand for his crimes. While he isn't caught for stealing, Fergus does eventually lose a hand and Jamie upholds his promise.
The simple answer is no. Claire and Jamie don't have any more children after Brianna. Claire heads through the stones while pregnant with Brianna at the end of the second season/book. She spends 20 years in the 20th century, and she and Frank don't have any children together.
As a time traveler, he has lived during the 1630s and possibly other eras. He first attempts to travel forward beyond his own projected lifetime in 1778, with the help of Master Raymond.
And it has fans wondering why producers replaced the original Fergus actor Romann Berrux, writes the Express. The hit Starz series has a huge ensemble cast including the likes of current Fergus star César Domboy. French star Domboy first joined in 2017, appearing in the season three episode A.
He may never have called Jamie “Dad,” but Jamie has been the only father figure he's ever known. He's always looked up to Jamie, and this moment shows that Jamie continues to respect Fergus and call him family.
Claire Fraser was born on October 20, 1918.
That would make her 27-and-a-half at the time she and Jamie meet in the books, while Jamie's barely 22. This would make Claire five and a half years older than Jamie.
In the novels, Marsali and Fergus apparently know. They haven't been told on-page, but Diana Gabaldon confirms that the two know that Claire, Bree, and Roger are time travelers.
Following the Battle of Culloden, Fergus continues to live at Lallybroch, and Jenny Murray tutors him with the rest of her children. He sometimes brings food to Jamie, who lives in a cave near the estate.
Berrux was simply replaced by Domboy because the makers needed an older actor to show the passage of time with Fergus growing up. The actor would have been around 14 or 15 when Outlander season three was filmed, while Domboy was about 26 or 27.
Fergus' declining emotional state in the show is depicted pretty much as it is in A Breath of Snow and Ashes. He's distraught over the fact that his newborn son, Henri-Christian, is a dwarf. He feels ineffectual in both protecting and providing a life for his family. And he's been drinking too much, too often.
When Claire finds more bruises on Marsali's wrist, she asks her straight up if Fergus is doing this to her. Marsali explains she was so fed up with him being drunk that she lost her temper and attacked him — he grabbed her to defend himself.
In the dramatic final episode, pregnant Marsali (Lauren Lyle) was beaten and Claire was kidnapped and raped by Lionel Brown (Ned Dennehy).