Due to patents’ industrial and economic importance, it is no surprise that their regulatory framework has been the subject of discussions for many years, also in Europe. Historically, given the limited territorial nature of patents protecting inventions, they were rather a matter of different national laws that in turn were rooted in customary law. The differences concerned substantive patentability criteria as well as procedural rules on the enforcement of patent rights, such as the required novelty standard or the duration of patent protection. The issue of heterogeneity of patent legal systems had been raised already back in 1873 at the first International Congress of Vienna, subsequently in 1883 when the “Paris” International Union for the Protection of Industrial Property was created and later in 1932, at the Congress of London. However, the outcomes concerning the harmonisation of patent law were rather limited, particularly for Europe. (First paragraph)