Furthermore, in so far as the application of national law, in the procedural context in question, may have the effect of depriving the proprietor of an EU trade mark of his right, it is essential that the General Court is not deprived, notwithstanding possible lacunae in the documents submitted as evidence of the applicable national law, of the real possibility of carrying out an effective review. To that end, it must therefore be able to confirm, beyond the documents submitted, the content, the conditions of application and the scope of the rules of law relied upon by the applicant for a declaration of invalidity. Consequently, the judicial review conducted by the General Court must meet the requirements of the principle of effective judicial protection.

Third, in accordance with Article 65(1) and (2) of Regulation No 207/2009 on the European Union trade mark, the General Court has jurisdiction to conduct a full review of the legality of the Office’s assessment of the particulars submitted by an applicant in order to establish the content of the national law whose protection he claims.

Second, as regards, more specifically, the Office’s obligations, the Court has held that, where an application for an EU trade mark to be declared invalid is based on an earlier right protected by a rule of national law, the competent bodies of the Office must first assess the authority and scope of the particulars submitted by the applicant in order to establish the content of that rule. In addition, since the decision of the competent bodies of the Office may have the effect of depriving the proprietor of the trade mark of a right that has been granted to him, the scope of such a decision necessarily implies that the authority which takes it is not limited to the role of mere validation of the national law as submitted by the applicant for a declaration of invalidity.

As regards the allocation of the various roles between the applicant for a declaration of invalidity, the competent bodies of the European Union Intellectual Property Office and the General Court, Rule 37 of Regulation No 2868/95 implementing Regulation No 40/94 on the Community trade mark provides that the applicant must provide particulars showing that he is entitled under the national law applicable to lay claim to an earlier right protected under national law. That rule requires the applicant, in order to be able to have the use of an EU trade mark prohibited by virtue of an earlier right, to provide the Office with, not only particulars showing that he satisfies the necessary conditions under the national law which he seeks to have applied, but also particulars establishing the content of that law.

The review by the European Union Intellectual Property Office and by the General Court must be conducted in the light of the need to ensure the practical effect of Regulation No 207/2009 on the European Union trade mark, which is to protect the EU trade mark.

If the General Court were to restrict itself to applying the national law as it was interpreted by the national courts at the time of the decision by the Board of Appeal of the Office, this could result in the refusal to register an EU trade mark or its revocation, even though the relevant national law does not provide, as of the time at which the General Court issues its decision, any basis for so doing.

That result would run counter not only to the requirement of ensuring the practical effect of Regulation No 207/2009, but also, by depriving the General Court of the real possibility of conducting in an effective manner the full review of legality mentioned in paragraphs 37 and 38 of the present judgment, to the principle of effective judicial protection.

It follows that, in assessing the protection granted by national law, the General Court must apply a rule of national law as interpreted by the national courts at the time at which it issues its decision. It must therefore also be able to take into consideration a decision originating from a national court, issued after the adoption of the decision of the Board of Appeal of the Office.

It is true that the taking into consideration of a decision of a national court issued after the adoption of the decision of the Board of Appeal of the Office could lead the General Court to undertake an assessment of a rule of national law which differs from that of that Board of Appeal. However, since the judicial review of the assessment of national law by that Board of Appeal, conducted by the General Court, would be a full review of legality, the fact — revealed after the adoption of the decision of the same Board of Appeal — that that decision was based on an incorrect interpretation of national law cannot prevent that error from being corrected.

This conclusion is not called into question by the case-law according to which, first, the General Court must, in principle, confine itself, on the basis of the particulars underlying the Board of Appeal’s decision, to finding the decision that the latter should have reached, second, the General Court may annul or alter a decision against which an action has been brought only if, at the date on which that decision was adopted, it was vitiated by one of those grounds for annulment or alteration referred to in Article 65(2) of Regulation No 207/2009, and, third, it may not annul or alter that decision on grounds which come into existence subsequent to its adoption.

While it is true that that principle has a broad scope and prohibits, inter alia, the General Court from annulling or altering the decision of the Board of Appeal of the Office by taking into account facts which came into existence after that decision had been adopted or by applying substantive legal provisions which were not yet in force at the time of that adoption, it does not, by contrast, prohibit the General Court from taking into account, in disputes concerning the application of Article 8(4) of Regulation No 207/2009, an evolution in the interpretation, by the national courts, of the rule of national law examined by the Board of Appeal of the Office. That rule of national law was one of the particulars subject to assessment by that Board of Appeal and the application of that rule by the same Board of Appeal is subject, pursuant to Article 65(2) of that regulation, to a full review of legality by the General Court.

However, in accordance with the principle that the parties should be heard, which comes under the right to a fair trial laid down in Article 47 of the Charter of Fundamental Rights of the European Union, the taking into consideration by the General Court of a decision of a national court issued after the adoption of the decision of the Board of Appeal of the Office is subject to the condition that, as in the present case, the parties have had, before the General Court, the opportunity to submit observations on the relevant national decision.

(see paras 39-46)