How long had the Romanov dinasty been ruling in Russia?

300 years

The Last Days of the Romanovs For 300 years the Romanovs ruled Russia as tsars. But as World War I brought Russia to revolution, Tsar Nicholas II and his family were overthrown.

Explanation:

answer: what was the us involvement in ww1? although the u.s. tried to remain neutral when ww1 broke out, it finally joined on april 6, 1917 after declaring war on germany. the reason for america to become involved in ww1 was germany's unrestricted submarine warfare, which had already sunk several american merchant ships.

explanation:

warfare was the primary means of cultural transmission in both regions.