General Alexander Spiridovitch, Chief of Secret Security Police to the Emperor, in his Memoirs states as a matter of fact that Nicholas II asked Minister of Justice Tcheglovitov to prepare a report about succession rights to the Valdimirovich descendants. The report stated without a question that because Maria Pavlovna was not Pravoslavnaya on the day she was married, her children had no succession rights. The Ukaze issued by Alexander II giving consent when Vladimir married Maria Pavlovna stipulated specifically that ONLY Vladimir kept his rights, not his children. Tcheglovitov was clear in the report that none of the Vladimirovtichi had succession rights to the Imperial Russian Throne because her adoption of Orthodoxy decades later was not "retroactive" because her sons were born to a non Pravoslavnaya mother. I hope that this document still might exist in GARF and one day it will be found. Spiridovitch was most clear that there were THREE copies of his report, one for Nicholas II, one was sent to Maria Pavlovna, and the third retained in his records.
Actually, Spiridovich states a great deal of things as a "matter of fact" in his memoirs which are inaccurate, incomplete, or misremembered. The Ukaze which was mentioned here is misquoted. Regarding HIH Grand Duke Kirill Vladimirovich and his succession rights and the succession rights of his children. You state (as have many western scholars) that Kirill Vladimirovich had no right of succession to the Russian throne because of the Lutheran faith of his mother at the time of his birth. This is, in fact, a widely repeated fallacy -- it was among the many pieces of émigré disinformation which was spread in the west after 1918 by supporters of Nikolai Nikolaevich aimed at people who were unfamiliar with private arrangements within the Imperial Family, as well as the specific nature of the succession laws.
There was a "Familial Decree" at the time of the marriage of Grand Duke Vladimir to his wife Grand Duchess Maria Pavlovna concerning this exact matter. Because of Maria Pavlovna's reticence regarding conversion, the following document was drawn up, signed, countersigned, and announced in the Russian Imperial Senate (full citation follows the quote for the original Russian Source material):
“Having allowed my son, Grand Duke Wladimir Alexandrovich, to enter into marriage with Her Grand Ducal Highness Duchess Marie of Mecklenburg-Schwerin; and indicating our agreement that Her Highness Duchess Marie, in accordance with her special familial circumstances, is not required before her betrothal and marriage to convert to the Orthodox faith, I deem it right to establish in this present Familial Decree the following unalterable rules with respect to this marriage: (1) If, by God’s inscrutable will, the succession to the Throne should fall to my son, Grand Duke Wladimir Alexandrovich, and his spouse should remain in the Lutheran faith, then my son, Grand Duke Wladimir Alexandrovich, in accordance with Article 142 of the Fundamental Laws, may not take up the right of succession other than after the conversion of his spouse to the Orthodox faith; (2) If the spouse of Grand Duke Wladimir Alexandrovich should not convert to the Orthodox Faith at the time of the passing of the Succession to him, then he should be regarded as having of his own free will renounced his said rights, in full accordance with the contents of Articles 15 and 16 of the Fundamental Laws; (3) If, by God’s inscrutable will, the spouse of Grand Duke Wladimir Alexandrovich, having not converted to the Orthodox faith, should die before the passing to him of the right of succession, then, his marriage to a person of another faith having ended, he will preserve his right of succession to the Throne; (4) In the event indicated above in section 2 concerning the renunciation of Grand Duke Wladimir Alexandrovich, and in the same manner if, by God’s inscrutable will, Grand Duke Wladimir Alexandrovich should die before his spouse should convert to the Orthodox faith, the children born of this marriage retain full rights to the succession and are Members of the Imperial House in the order of succession set by the Fundamental Laws.”
This ukaz' was signed by Emperor Aleksandr II, by the Tsesarevich Aleksandr, and by the bridegroom, Grand Duke Vladimir Aleksandrovich. Dr. Stanislaw V. Dumin found this memorandum in the Russian State Historical Archive (GARF) in Moscow. I am grateful to Brien Horan for having brought it to my attention and to Professor Russell Martin for his English translation. The original is at GARF, Fond 468, subsection 46, number 63. CF Dr. Dumin’s analysis of this document is in the Chronicle of the Historical and Genealogical Society, issue 14/15 (58/59), Moscow, 2009. (The numbering of the Fundamental Laws was different in 1874 than in 1917, when the monarchy fell.) It was first published in english by Brien Horan in his article "The Russian Succession in 2013" published in the Royal Russia Annual Vol. No. 3, 2013.
You can see from this Ukaz' that even if Grand Duchess Maria Pavlovna had NOT converted to Orthodoxy, there was no question that her son, Kirill Vladimirovich, and all subsequent issue were in line for the throne with full dynastic rights. The conversion of the Grand Duchess Maria Pavlovna may be regarded charitably to have been a purely religious act of conscience on the death of her husband, or uncharitably as a political move to remove the last publicly perceived though legally irrelevant obstacle to her son's inheritance of the throne.
