In the first part of Part V three themes are employed: the journey to Emmaus, the approach to the Chapel Perilous (see Miss Weston's book), and the present decay of eastern Europe.
Jessie L. Weston's book on the Grail legend:From Ritual to Romance was mentioned in Eliot's first note.
The part about the decay of eastern Europe probably starts at
line 366.
See
Eliot's note to line 366
or the
allusion page for that line.