The
1866 Constitution of Romania was the fundamental law that capped a period of nation-building in the
Danubian Principalities, which had united in 1859. Drafted in a short time and using as its model the
1831 Constitution of Belgium, then considered Europe's most liberal, it was substantially modified by Prince (later King)
Carol and adopted by the Constituent Assembly. The newly installed Prince then promulgated it on July 1; this was done without input from the major powers, including the
Ottoman Empire, which still had formal sovereignty over Romania.