Question: In what year did the three original  cantons join with five other cantons to form the "Old Confederacy" of eight states?
Sentence: By 1353, the three original cantons had joined with the cantons of Glarus and Zug and the Lucerne, Zürich and Bern city states to form the "Old Confederacy" of eight states that existed until the end of the 15th century.
Answer in sentence: yes