The title grand prince is the English translation of the Russianвеликий князь. The Slavicknyaz and the Baltickunigaitis (both nowadays usually translated as prince) is a cognate of king.[1]
Grand dukes of Russia of the House of Romanov-Holstein-Gottorp
Ioann Konstantinovich was born as a Grand Duke of Russia with the style Imperial Highness, but at the age of 9 days, an Ukaz of his cousin Emperor Alexander III of Russia stripped him of that title, as the Ukaz amended the House Law by limiting the grand-ducal title to grandsons of a reigning emperor. As a result, he received the title Prince of the Imperial Blood (Prince of Russia) with the style Highness