The Medieval Church · 1053
Letter Against the Latin Usages
Leo of Ohrid · 11th century
What it is
A protest against Western practices — unleavened bread at the eucharist, fasting on Saturdays, no alleluia in Lent — sent to a bishop in southern Italy.
Why it lasted
The letter that set off the exchange ending in the mutual excommunications of 1054, and evidence that the schism turned as much on custom as on doctrine.
Where to read it
This work is in the public domain and can be read in full, free, at the archives below. The Library catalogues it; it does not host the text.
These open a search on each archive rather than a direct link, which is the honest way to point at an edition nobody here has checked line by line.
Read next