The website Canticum Salomonis has a carefully researched piece about the history of the Office for All Souls’ Day. It begins with links to two previous posts on the same site about the origins and structure of the Office which are equally insightful and informative and can also be accessed at origins of the Office of the Dead and All Souls, and the reforms All Souls underwent in the Neo-Gallican liturgies.
This latest article looks at the changes enacted under Pope St Pius X. The discussions recorded appear in many ways as lively as those in more recent decades.
The reposted article can be seen at REPOST: Novæ Mutationes: St Pius X’s New Office of All Souls