The reporting period underlying this 20th edition of the Swiss Yearbook of European Law was shaped by Russia's war of aggression against Ukraine and the subsequent energy and migration crisis. Against this backdrop, Switzerland's participation in the acquis communautaire is becoming increasingly complex, and the influences of EU law on the Swiss legal system must not be underestimated. For 20 years, a central concern of the yearbook has been the scientific-theoretical as well as practical preparation of the interaction between Swiss law and the EU legal order, as well as the various bilateral agreements, in order to make these developments accessible to those interested from administration, practice, and academia, as well as to students.