The textbook is a rarity as it explores the functions of diplomacy from a practical perspective on diplomatic activity. This in-depth study redefines diplomacy, distinguishing it from conventional definitions. While the historical context of diplomacy is briefly discussed, the spotlight then turns to six diplomatic classics: Niccolo Machiavelli, Hugo Grotius, Ernest Satow, Harold Nicolson, Henry Kissinger, and Geoff R. Berridge. Thus, their brief biographies and core diplomatic tenets are revealed. Many aspects of the theories of international relations are covered, including liberalism, realism, neoliberal institutionalism, and constructivism. Diplomatic protocol is analysed as an instrument, guiding the position of political and diplomatic representatives according to the ranking system. Practical examples abound, with illustrations of protocol rules from the United States, the United Kingdom, Japan, Australia, France, Germany, China, and Kosovo. The pivotal role of language in diplomacy is discovered as a communication tool, alongside an examination of its specific significance. It also delves into public diplomacy, exploring its evolution over the three two decades, heavily influenced by media developments. The book also focuses on the establishment of sociology of diplomacy as a new independent discipline. It sheds light on the necessary scientific research procedures, both theoretical and empirical, grounded in descriptive methodologies, understanding, and sociological explanations of the diplomatic phenomena. A crucial part of the book examines the connection between diplomacy and ethics and asserts that while states naturally pursue their interests, adherence to ethical principles must remain steadfast. Finally, gain insights into the traits and characteristics of a modern diplomat as the book draws to a close.