 If the Empress did not give birth to an heir, the Emperor could take a concubine, and the son he had by that concubine would be recognized as heir to the throne.This law, which was promulgated on the same day as the Meiji Constitution, enjoyed co-equal status with that constitution.Article 2 of the Constitution of Japan, promulgated in 1947 by influence of the U.S. occupation administration, provides that "The Imperial Throne shall be dynastic and succeeded to in accordance with the Imperial Household Law passed by the Diet."