A letter is one person's written message to another pertaining to some matter of common concern. Letters can serve several purposes: when intimates are forced to spend time at great distances from one another, letters allow them to maintain the relationship; rulers, scholars, merchants, officials, and professionals use them to conduct affairs with their far-flung correspondents; poets and other writers may also use them as vehicles for self-expression. Letters contribute to the protection and conservation of literacy. Letters have been sent since antiquity and are mentioned in the Iliad. Both Herodotus and Thucydides mention letters in their histories. yo
Historically, letters have existed from the time of ancient India, ancient Egypt and Sumer, through Rome, Greece and China, up to the present day. During the seventeenth and eighteenth century, letters were used to self-educate. Letters were a way to practice critical reading, self-expressive writing, polemical writing and also exchange ideas with like-minded others. For some people, letters were seen as a written performance. For others, it was not only seen as a performance but also as a way of communication and a method of gaining feedback. Letters make up several of the books of the Bible. Archives of correspondence, whether for personal, diplomatic, or business reasons, serve as primary sources for historians. At certain times, the writing of letters has risen to be an art form and a genre of literature, for instance in Byzantine epistolography.
In the ancient world letters were written on a various different materials, including metal, lead, wax-coated wooden tablets, pottery fragments, animal skin, and papyrus. From Ovid, we learn that Acontius used an apple for his letter to Cydippe.