The referential relationship is the relationship between what

A referential constraint enforces a one-to-one relationship between the values in referencing columns (of the foreign key) and the referenced columns (of the primary key or unique constraint). ... The same data values can appear in the constrained columns of both tables.

the answer is: tabard inn, southwark.

in "the canterbury tales," by geoffrey chaucer, the twenty-nine diverse group of pilgrims is staying at a tavern in southwark, london, as they are traveling to canterbury. they wish to visit the relics of saint thomas becket in canterbury   cathedral in order to him for his when they underwent necessities.