There began a refreshing atmosphere of unity and Iranian patriotic sentiments during the constitutional era. During the Pahlavi dynasty (1925–1979), Iranian nationalism experienced a resurgence due to the Pahlavi government's bolstering of patriotic sentiment. After the Iranian revolution, there has been a resurgence of nationalism within the Islamic Republic of Iran in the wake of the Iran student protests, July 1999 and the Islamic Republic's autocratic policies over its forty year existence.