A Swallow Song - Dick Farina
https://mudcat.org/thread.cfm?threadid=1901   

"the story as I remember it is that Richard wrote this song for his sister-in-law Joan Baez during or after a visit to San Juan Capistrano when the swallows returned (traditionally March 19th).
https://constantname.blogspot.com/2014/11/more-than-you-want-to-know-about.html

Mission San Juan Capistrano is named after Saint John of Capistrano -- San Giovanni da Capestrano. Again from Wikipedia: "John was known as the "Scourge of the Jews" for his fanatical anti-semitism. In 1447 he offered the Pope a small fleet on which to load all the Jews of the papal states in order to ship them to some faraway land. Between 1451 and 1453, his fiery sermons against Jews persuaded many southern German regions to expel their entire Jewish population, and at Breslau some were burned at the stake."
http://en.wikipedia.org/wiki/John_of_Capistrano "