pin one's hopes on, to

pin one's hopes on

Also, pin one's faith on. Put one's hope or trust in someone or something, as in She'd pinned her hopes on an early acceptance to the college but it didn't materialize. This term, dating from the 1500s, originated as pin one's faith on another's sleeve and may have alluded to the practice of soldiers wearing their leader's insignia on their sleeves. By the 1800s, however, it acquired its present form.
See also: hope, on, pin

pin one's hopes on, to

To attach one’s aspirations for success to a particular event, individual, or the like. This term began in the sixteenth century as pin one’s faith on another’s sleeve and appeared in this form in John Ray’s 1678 proverb collection. Ebenezer Brewer believed it came from the feudal practice of troops wearing their leader’s badge on their sleeves. Since badges and loyalties sometimes changed, people became wary of judging where one stood from such a badge and said they would not pin their faith on someone’s sleeve. By the nineteenth century, however, hopes were replacing faith (at least in this term) and sleeves were lost altogether.
See also: hope, pin