The fourth volume of the Balkan Yearbook of European and International Law (BYEIL) presents nine new articles offering scholarly insights into a variety of legal issues, with a special focus on the countries of Southeast Europe. All six articles in the special section reflect the authors' efforts to untangle difficult questions concerning family property in private international law. Addressing a range of topics, leading national experts in the respective areas discuss Bosnian and Herzegovinian, Croatian, Greek, Lithuanian and Turkish law. In turn, the general sections on European law and international law include three articles on diverse topics in private and public law, from a fresh take on the legal and practical effects of Brexit over EUTMs, and the legal nature of cryptocurrencies in different jurisdictions, to difficulties establishing the rule of law in Bosnia and Herzegovina.