The series begins in 1879 as Forsyte family members gather at Uncle Timothy's and exchange gossip about younger family members: Winifred, who is engaged to the financially irresponsible Montague Dartie, and Young Jolyon, who is having an affair with his children's Austrian governess.
Young Jo decides to leave his wife to be with Helene and their unborn child. This causes Old Jolyon to write him out of his will in favor of granddaughter June. Meanwhile, Soames Forsyte becomes smitten with the smoking hot Irene Herrin.
Young Jo's first wife dies in an accident leaving him and Helene free to marry. Winifred begs her father to help ease Monty's debts. Helene gives birth to a son nicknamed "Jolly." Old Jolyon assumes parental authority over granddaughter June. Soames continues to pursue Irene who finally consents to marriage.
Several years pass. June Forsyte gets engaged to architect Phillip Bossiney. Irene endures a troubled marriage to Soames but sparks fly when she meets Phillip. Helene becomes ill and Old and Young Jolyon take steps toward reconciling.
Unaware of his wife's attraction to the man, Soames hires Phillip Bossiney to build a mansion for them at Robin Hill. Old Jolyon visits Jo and Helene at their home and tries to mend the rift. Monty Dartie continues to rack up debts, putting a strain on his marriage to Winifred.
Irene's affair with Bossiney becomes public and Soames threatens the architect with legal action concerning cost overruns at Robin Hill. Then he violently asserts his marital rights with Irene.
After being raped by her husband, Irene waits on Bossiney to run away with him but the architect is nowhere to be found. He also fails to show up at court and thus loses a legal action to Soames. Then the Forsyte men are called to identify a body at the morgue..............................
Distraught after Bossiney's death, Irene returns to Soames for one final night and then leaves him forever. Four years then pass and we find Jo and his family living in the house at Robin Hill. Old Jolyon then assumes room temperature but leaves a bequest in his will for Irene.
Helene dies and June strikes out on her own. Monty deserts Winifred and sails to Buenos Aires with a Brazilian skank. Jo's daughter, Holly, meets Winifred's son, Val, and is attracted to him. After meeting Annette Lamotte, Soames hunts down Irene to get a divorce.
Val and Holly contnue their romance despite the objections of her brother, Jolly. Winifred and Soames try to get out of their respective marriages. Irene flees to Paris where she encounters Jo and the two fall in love.
Soames gets enough evidence against Irene to proceed with his divorce. Val and Holly become engaged in secret. Monty returns from Argentina a broken man. Winifred has pity on her hubby and takes him back. The Boer War begins and several Forsyte family members participate.
Jolly dies in the Boer War while Val and Holly marry and decide to remain in South Africa. Soames is granted a divorce and he marries Annette, hoping to father a son. Jo and Irene get married and she gives birth to their son Jon. Annette then gives birth to a daughter, Fleur, who will be the only child of Soames Forsyte.
Twenty years pass skipping over World War I. The third generation of Forsytes take center stage. Jon decides to become a farmer. He meets his cousin Fleur for the first tiime at June's art gallery. The two become infatuated when they meet again at Holly and Val's horse farm not knowing of the exact cause of the feud between their respective branches of the Forsyte family.
The elder Forsytes hide details of the family feud from Jon and Fleur. Aspiriing politico Michael Mont falls for Fleur and wins the respect of Soames. Jo's health begins to fail and he tries hiding his condition from Irene. Fleur is told the secret of the Forsyte family feud.
Fleur tries to get Jon to the altar before he learns the truth behind the family feud but the dying Jo tells him. Jon then chooses his mother over Fleur and they make plans to move abroad. Fleur then finds comfort in the arms of Michael Mont.
Jon and Irene move to Canada. Fleur marries Michael Mont. Two years pass and more characters are added to the series. Mont's father gets Soames to join the board of an insurance company where he immediately becomes suspicious of the firm's managing director, Elderson. Meanwhile, a worker at Michael's publishing firm named Bicket who got sacked tries to make enough money to emigrate to Australia.
Soames' suspicions of Elderson are confirmed and he presses Fleur for a grandchild.
Michael is tormented by the thought that Fleur might be interested in poet Wilfrid Desert. He then encounters June who lets slip that Fleur married him while on the rebound. Fleur becomes pregnant at last while the Bickets have enough money to immigrate to Australia.
The Bickets leave for Australia. Elderson flees too after admitting his larceny leaving Soames to face an angry group of stockholders. Fleur gives birith to a son named Kit.
In the Carolinas, Jon and Irene visit Ann and Francis Wilmot. Jon falls for Ann and they are married. Across the pond, Michael Mont is now a member of Parliament. Fleur busies herself throwing parties and after a row at one of them she finds herself threatened by a libel suit.
Marjorie Ferrar threatens Fleur with a libel suit but Soames seeks to turn the tables by proving Marjorie guilty of immorality.
Fleur's libel case goes to court. A settlement is finally reached but Fleur and Michael end up being ostracized socially as a result.
Fleur and Soames decide to take a trip around the world to avoid the fallout from the Ferrar case. Jon and his family decide to return to Great Britain for good. Michael asks June for specific details about the Forsyte family feud while Fleur, returned from abroad, plans a chance meeting with Jon.
Jon's wife, Anne, fears that she is no match for his first love, Fleur whose husband, Michael, likewise suffers from marital anxieties.
Soames begins having feelings of his own mortality. Holly asks Irene to settle with her and Val.
Jon succumbs to Fleur and immediately regrets it. Irene then has a long talk with Fleur and persuades her to back off. She then reconciles with Michael. Soames dies from injuries suffered from a fire in his picture gallery.