The history and the essential and important articles of the constitutional laws of Iran and its immediate neighbours are elucidated and compared. The article includes an analytical comparison of the 1906-07 and 1979 Constitutions of Iran. A brief analytical synoptic overview of world constitutions is also presented in order to obtain a balanced view of the process of constitutionalism and popular suffrage for men and women.In 1979, the Islamic Republic of Iran became the first country in the world to include a declaration for the preservation of the environment in its Constitution.Having compared the 1906-7 Constitution of Iran with a good number of others, it is very evident that the transformation of an autocratic monarchy into a constitutional one was in itself a great leap forward, at a time, when most of the world still lived under dictatorship.In Iran, a number of civil institutions have played their role for a whole century thanks to the 1906-07 Constitution, though far from perfect, nevertheless more or less accepted and functioning. These include a hundred years of direct parliamentary elections, and several years of presidential, municipal and other popular suffrage.The propagation of the 1906-07 Constitutional Movement of Iran has been paramount; it had greatly influenced the awakening of many other peoples of the neighbouring and regional countries. The 1908 re-institution of parliament in the Ottoman Empire, the 1911 Chinese Revolution, and the 1917 Revolution in Tzarist Russia were undoubtedly influenced by the Constitutional Movement of Iran.