I do research in privacy and as a result I became very interested in the concept's history. One slight problem is that the term "privacy" originates from an 1890 publication called The right to privacy by Warren & Brandeis. Before that there are some works relevant to the formation of the concept, but all within a few decades of that defining article. However, I can find hardly anything describing privacy before that time.

I do find a lot of sources of varying quality that describe what we nowadays associate with privacy. Some examples:

• Anthropological texts from the 17th century onward describing encounters with and studies of tribal life. They point to privacy-seeking behaviour, like couples in the Huron tribe getting intimate in the area surrounding the single room longhouse. This behaviour had a strong effect on seasonal birth rates. Or descriptions of tribal life where nudity was commonplace.
• Philosophy texts are possibly the best documented. Both Plato and Aristotle discuss private and public life, and so do the Romans. Pliny the Elder even complained about the same issues as contemporary celebrities: “Great fortune has this characteristic, that it allows nothing to be concealed, nothing hidden; it opens up the homes of princes, and not only that but their bedrooms and intimate retreats, and it opens up and exposes to talk all the arcane secrets.”
• Developments in housing, such as brick chimneys leading to the division of common houses into separate rooms. Or how increased wealth leads to smaller household sizes, a relation that still seems to be hold nowadays. The sources I have for this are all over the place though.

Researching privacy before its conception is a challenging task, because seeing how those findings relate to privacy is my personal interpretation. I encountered pieces of the picture in a wide range of topics. These include art, architecture, government administration, public (and political) culture, philosophy, religion and sexuality. By approaching the subject from multiple angles, I hope to develop a well-rounded image of privacy throughout history.

So far I'm finding my way through Ancient Greece and Rome, as those happen to be the historical periods I'm most familiar with. Before or after that I'm feeling rather blind and I could really use a trained eye to point me in interesting directions. As a result, my query is rather broad:

What are interesting works that can further my investigation of the concept of privacy throughout (mostly European) history?

I hope I managed to describe what I'm looking for, but feel free to ask for clarification. Any help is appreciated.