How are you defining civilization and king/queen/emperor? There are certainly plenty of cultures who developed a state without a monarch-type ruler. You could hardly call the k'uhul ajaw of a Maya city state the same kind of leader as the British monarch in the 14the century, but both have been called kings. Both positions were hereditary, but ruling the entire land of England and ruling the city of Tikal and its assorted holdings are rather different; there was never a single "king" of all the Maya. Can you really be king if your neighbor has the same title legitimately, but in an entirely separate polity? Or are you asking just about governments without any kind of single leader/figurehead, with no concern for the function of that individual?