6.  At the relevant time the first applicant was Chief of Staff of the Ministry of the Interior. He owned an apartment together with his wife until 1980, when they donated it to their son. Thereafter, the first two applicants lived as tenants in a State-owned apartment. 7.  On 27 November 1985, the first applicant was granted the tenancy of another State-owned apartment which belonged to the housing fund of the Ministry of the Interior. The apartment had four rooms and covered 132 square metres. 8.  On 15 January 1986 the first and the second applicants purchased the apartment from the Ministry. For the purposes of the transaction, the first applicant submitted declarations stating that he lived with his wife, their granddaughter and the second applicant's mother. 9.  On 27 January 1992 the first and second applicants transferred the apartment to their son's family (the third and fourth applicants). 10.  On 3 June 1992 the Ministry of the Interior brought a rei vindcatio action against the applicants claiming that the 1986 transaction was null and void as being contrary to the relevant provisions on the sale of housing. 11.  On 7 October 1992 the Sofia District Court held its first hearing in the case. Noting deficiencies in the claim, the court instructed the plaintiff, the Ministry of the Interior, to amend it. 12.  The Ministry did not comply with that instruction until April 1993, which caused the adjournment of the hearings listed for 2 December 1992 and 4 March 1993. 13.  The examination of the case thus began on 7 July 1993. Although the fourth applicant had not been properly summoned, her lawyer gave his consent for the hearing to proceed. 14.  The hearing listed for 3 November 1993 was adjourned, as the Ministry of Finance, whose participation was mandatory in such cases, had not been summoned. 15.  At a hearing held on 2 February 1994 the Ministry of the Interior requested an adjournment to enable them to submit documents pertaining to the 1986 sale. 16.  The hearing was resumed on 14 April 1994. The plaintiff introduced an amendment to the claim and sought an order requiring the first two applicants to appear personally and reply to questions regarding their housing situation at the time they had obtained the apartment in question. The court issued that order and adjourned the hearing. 17.  On 1 June 1994 the first applicant could not be questioned as he had been taken ill. On 8 July 1994 he was questioned by another judge in the town where he was undergoing medical treatment. 18.  The Sofia District Court resumed the examination of the case on 20 September 1994, when the parties made their final submissions. The court reserved judgment. 19.  By a judgment of 4 November 1995 the District Court found, inter alia, that the apartment at issue had been larger than permitted by law for a family like that of the first and second applicants. The relevant rules provided that the term “family” could only include the spouses, their minor children and the spouses' parents, if they lived together. At the relevant time, however, the children of the first and the second applicants had reached the age of majority. Their granddaughter could not be considered as a member of the family for the purposes of the housing regulations. Also, it was unclear whether the second applicant's mother had actually lived with the first and second applicants. In these circumstances the family had had two members and had only been entitled to one room. It followed that the 1986 sale-purchase transaction was null and void. As a result, the first and second applicants had never become owners and could not have validly transferred their title to the third and fourth applicants. The court granted the Ministry's rei vindicatio claim. 20.  On 30 November 1995 the applicants appealed to the Sofia City Court. On 15 February, 18 April, 10 June, 14 October and 5 December 1996 the hearing could not proceed as the Ministry of the Interior had not been properly summoned. That was due to the fact that the summons receipts had not been filled out properly. The appeal was eventually heard on 27 February 1997. 21.  By a judgment of 19 June 1997 the Sofia City Court quashed the lower court's judgment and dismissed the claims of the Ministry of the Interior. It found, inter alia, that while it was true that the first and second applicants had obtained an apartment exceeding their housing needs and thus in violation of the relevant regulations, that fact did not entail nullity ab initio of the sale contract. 22.  On 8 August 1997 the Ministry of the Interior submitted a petition for review (cassation) to the Supreme Court, which later became the Supreme Court of Cassation. A hearing was held on 18 November 1998. 23.  On 2 February 1999 the Supreme Court of Cassation quashed the Sofia City Court's judgment and upheld the Sofia District Court's judgment, thus granting the rei vindicatio claim. The court held that the provisions regulating the size of apartments on the basis of housing needs, as in force at the relevant time, had established strict rules whose violation entailed nullity ab initio.