A campaigner has been successful in her claims of libel, it has emerged.
Erin Pizzey took action against Macmillan, which published Andrew Marr's book A History of Modern Britain, the BBC reports.
Her case centred on claims that she had supported British terror group the Angry Brigade during the early 1970s.
In a recent development, Macmillan - which has operations in more than 80 countries across the globe - accepted that she had not been a member of the group.
The firm agreed to pay Ms Pizzey undisclosed damages and apologised for the distress and embarrassment caused to her.
A solicitor acting on behalf of Macmillan said that Mr Marr had been trying to make a complimentary reference to Ms Pizzey, but accepted that the phrasing could have been misunderstood.
After the hearing at the high court, Ms Pizzey, who is now 70 years old, said: "I am both relieved and delighted that this matter has been amicably resolved."