The earliest mention of the flag occurs during the reign of Alexis I, in 1668, and is related to the construction of the first Russian naval ship, the frigate Oryol. According to one source, the ship's Dutch lead engineer Butler faced the need for the flag, and issued a request to the Boyar Duma, to "ask His Royal Majesty as to which (as is the custom among other nations) flag shall be raised on the ship". The official response merely indicated that, as such issue is as yet unprecedented, even though the land forces do use (apparently different) flags, the tsar ordered that his (Butler's) opinion be sought about the matter, asking specifically as to the custom existing in his country.