Wendy Craig was asked to play Aunt Juley as she had done in the first series but was not available because of her regular role in The Royal (2003).
Corin Redgrave (Old Joleyn Forsyte) and Kika Markham (Mme Lamotte) were married in real life
The series as it is shown on Amazon Prime divides Season One into eight of approximately 55 minute each, and Season Two into five episodes. Whereas, it was originally shown as six episodes for Season One, and four episodes in Season Two.
Ann Bell (Aunt Hester) and Robert Lang (Swithin) were real life husband and wife
Rupert Graves (as Young Jolyon) and Gillian Kearney (as June) play father and daughter, but there is actually just under nine years difference in their ages.