There are three sources of European Union law: primary law, secondary law and supplementary law.
principles of law. It has enabled the Court to bridge the gaps left by primary and/or secondary law.
Internationa l law is a source of inspiration for the Court of Justice when developing its case la w. The Court
case law of the Cour t of Justice. They have a llowed the Court to implement rules in different domains of
which the treaties make no mention.
general pr inciples of law.
Narrowly, the preponderance of EU law sources, from quantitative point of view, is given both by
the establishing treaties (as primary, principal sources) and by other rules contained in the
documents (acts) adopted by the Union institutions in the implementation of these treaties (as
derived, secondary sources).
More broadly, however, EU law is: all the rules (of law) applicable in EU legal order, some
of them even unwritten; the general principles of law or the jurisprudence of the Court of Justice;
the rules of law whose origin is outside the Union legal order, originating from external liabilities
of the Communities, of EU, respectively, and the co mplementary law derived from con ventional
acts concluded between the member states, for enforcing the Treaties. Further, we shall analyze,
in synthesis, the features of the unwritten sources of European Union law.
2. General principles of EU law2
Special attention, within the unwritten sources of EU law, should b e paid to the general
principles of law, because they have a considerable contribution to the process of establishing EU
law. Established by the Luxembourg Court of Justice case law, the general principles of law are
an important factor in strengthening and developing the EU legal system; this is possible due to
their essential characteristic, namely the need to be consistent with the specificity of this legal
system unique in the world.
Lecturer, PhD, Faculty of Law, “Nicolae Titulescu” University of Űucharest (e-mail:
1 Dumitru Mazilu, “In tegrare European. Drept comunitar i Instituii Europene”, Lumina Lex
Publishing House, Bucharest, 2000, p. 69.
2 For details, see Mihaela Augustina Dumitraşcu, “Dreptul Uniunii Europene şi specificitatea acestuia”,
Universul Juridic Publishing House, Bucharest, 2012.