The Merriam-Webster Encyclopedia of Literature
Sequence of three novels linked by two interludes by John Galsworthy. The saga chronicles the lives of three generations of a monied, middle-class English family at the turn of the century. As published in 1922, The Forsyte Saga consisted of the novel The Man of Property (1906); the interlude (a short story) "Indian Summer of a Forsyte" (1918); the novel In Chancery (1920); the interlude "Awakening" (1920); and the novel To Let (1921). Soames Forsyte, a solicitor and "the man of property," is married to the beautiful, penniless Irene, who falls in love with Philip Bosinney, the French architect whom Soames had hired to build a country house. Soames rapes Irene and proceeds to ruin Bosinney, who subsequently dies in a traffic accident in London. Irene returns to Soames. In Chancery concerns the love between Irene and Young Jolyon Forsyte, Soames's cousin. (The story of the last days of Old Jolyon, his father, is told in "Indian Summer of a Forsyte.") Irene and Soames divorce; she marries Jolyon and bears a son, Jon. Soames and his second wife, Annette Lamotte, have a daughter, Fleur. In To Let, Fleur and Jon grow up and fall in love; Jolyon informs his son of Irene and Soames's past relationship. Although Fleur is determined to marry Jon, he refuses. Fleur becomes the wife of Michael Mont, son of a baronet. Jolyon dies, and Irene leaves England. Soames discovers that Annette is involved in an affair with a Frenchman, as Irene had been.
The Forsyte Saga is a set of 3 novels and two "interludes" telling the story of a family in London over the course of a few decades, roughly 1880s-1920s. It was made famous by a 1960s British mini-series adaptation, which was re-made in 2002; both were broadcast on PBS. I wasn't sure if a novel penned in the early 1900s would be too much of a slog for me (also the almost 900-page length worried me), but the plot involving family secrets and infidelity kept me turning the pages. I would even say this would be a good beach read.
THE ORIGINAL DYNASTY. a DISHY, SCANDALOUS ACCOUNT OF THE 19TH CENTURY