28 AL-NASHIF v. BULGARIA JUDGMENT The interference with the applicants' family life cannot be seen, therefore, as based on legal provisions that meet the Convention requirements of lawfulness. It follows that there has been a violation of Article 8 of the Convention. 129. That being so, the Court is not required to determine whether the interference with the applicants' family life pursued a legitimate aim and, if so, whether it was proportionate to the aim pursued. IV. ALLEGED VIOLATION OF ARTICLE 13 OF THE CONVENTION 130. The applicants complained that they did not have an effective remedy against the interference with their right to respect for their family life. They invoked Article 13 of the Convention which provides: “Everyone whose rights and freedoms as set forth in [the] Convention are violated shall have an effective remedy before a national authority notwithstanding that the violation has been committed by persons acting in an official capacity.” 131. The Government maintained that the complaint under Article 13 was manifestly ill-founded, the applicants not having exhausted all domestic remedies 132. As the Court has stated on many occasions, Article 13 of the Convention guarantees the availability at the national level of a remedy to enforce the substance of the Convention rights and freedoms in whatever form they might happen to be secured in the domestic legal order. Article 13 thus requires the provision of a domestic remedy to deal with the substance of an “arguable complaint” under the Convention and to grant appropriate relief, although the Contracting States are afforded some discretion as to the manner in which they comply with to their Convention obligations under this provision. Giving direct expression to the States' obligation to protect human rights first and foremost within their own legal system, Article 13 establishes an additional guarantee for an individual in order to ensure that he or she effectively enjoys those rights. The “effectiveness” of a “remedy” within the meaning of Article 13 does not depend on the certainty of a favourable outcome for the applicant. Nor does the “authority” referred to in that provision necessarily have to be a judicial authority; but if it is not, its powers and the guarantees which it affords are relevant in determining whether the remedy before it is effective. Also, even if a single remedy does not by itself entirely satisfy the requirements of Article 13, the aggregate of remedies provided for under domestic law may do so (see Čonka v. Belgium, no. 51564/99, unreported, Kudła v. Poland [GC], no. 30210/96, ECHR 2000-XI, § 152, and T.P. and K.M. v. the United Kingdom [GC], no. 28945/95, ECHR 2001-V, § 107).