What is the origin of the idiom "call of duty" and when to use it?

The idiom "call of duty" has origins in the English language and dates back several centuries. The word "duty" can be traced to Middle English and has roots in Old French and Latin. It originally referred to a moral or legal obligation to perform a specific task or fulfill a responsibility. It is commonly employed in professions that involve serving others, such as military service, emergency response, healthcare, and teaching. In these contexts, ind