Romeo and Juliet (1968) IMDb Page
http://www.imdb.com/title/tt0063518/
The IMDb page for the film, which included notable quotes, trivia, cast and crew lists, etc.
The Question and Answer section for Romeo and Juliet (Film 1968) is a great resource to ask questions, find answers, and discuss the novel.
The beginning prologue only mentions that the feud between the Capulets and the Montagues stemmed from a grudge between the two families. I don't think the reasons why the feud started are ever explained.
The characters carry swords.
Juliet