[2] Together with his brother, Leonid, he owned the village of Protasovo, in the Saransky Uyezd (now Lyambirsky district) Penza Governorate.

[4] In 1890 he was appointed adjutant to Grand Duke Vladimir Alexandrovich as the Commander-in-Chief of the Imperial Guard and Saint-Petersburg Military District.

[2] In 1905, the son of Grand Duke Vladimir Alexandrovich, Kirill, was expelled from the Imperial House of Russia due to mismarriage.

The new commander, Grand Duke Nikolay Nikolayevich, dismissed Illya Tatischev on 6 December 1905.

[5] During WWI, Illya Tatischev served to the Chief Head of the Sanitary and Evacuation Unit of the Russian Red Cross Society Duke Alexander of Oldenburg.

[3] In October 1981, Count Ilya Leonidovich Tatischev was canonized by the Russian Orthodox Church Outside Russia as a new martyr under the name of Holy Martyr Warrior Illya (Russian: Святой Мученик Воин Илья).