The news of Baha'u'lla'h's spiritual success was spread through out the Iraqi regions, and also in the Persian regions. The Persian king tried to find an agreement with the Ottoman government to take Baha'u'lla'h back to Persia but that attempt failed. The Ottoman government asked Baha'u'lla'h to come to Constantinople (now Istanbul). Therefore, many friends and visitors gathered in Baghdad to hear the news and waited to see, and to pay respect for his departure. The house where he was staying at that time was too small to accommodate all these people coming to participate and bid farewell.

Surprisingly, one of the notable persons in Baghdad, named Najib Pasha, placed his garden park, called Najibiyyih, in the hands of Baha'u'lla'h. In this beautiful garden named by Baha'u'lla'h, Ridvan (paradise), he, together with his family, moved there on the 22nd April 1863, and remained there for twelve days and invited all his friends and visitors to that garden.

On the first day of his arrival, he declared himself 'Manyuzhiruhu'llah' (He Whom God make Manifest). These twelve days are celebrated by the Baha'is as the festival of Ridvan.

Holy Ridvan Celebration annually comes on the first day of Baha'i New Year (21st of March or first day of spring), it could continue for 12 days. Additionally in other times Baha'i people could celebrate individually or with family or friends at anytime of the year as they wish to celebrate for any good reason such as: receiving in health and prosperity and other positive achievements, pray to Baha'u'll'ah' for his messages from god and happy to be Baha'i.