Letters sent between former governor-general Sir John Kerr and Buckingham Palace will be released next week, shedding light on a controversial period of Australian history.
The National Archives will publish the 212 letters plus attachments - more than 1000 pages - online next Tuesday.
The decision follows a years-long legal battle by historian Jenny Hocking to gain access to the documents.
"It's a great day for our history, it's a great day for transparency," Professor Hocking told AAP on Thursday.
The so-called "palace letters" between Sir John and the Queen cover the time of Gough Whitlam's dismissal as prime minister.
Prof Hocking said it could mean history books on the explosive 1975 dismissal would have to be rewritten.
"We haven't had the benefit of knowing what was being said between the governor-general and the Queen," she said.
She said it was a huge holding of documents, considering most governors-general would have reported to the palace up to four times a year.
Prof Hocking, who lives in Melbourne, would be unable to see the documents herself due to the Victorian lockdown.
But she said a research assistant would be going to the archives while she reviewed them online.
"I'm so pleased with the outcome that whether or not I can be there in person is immaterial," Prof Hocking said.
In May, the High Court ruled the letters should be made public.
Archives director-general David Fricker said the letters would be released in full after staff examined them to check whether any information should be redacted.
"This is part of our history that we've all been waiting to get the full and complete story on," Prof Hocking said.
Australian Associated Press