Considering that the sovereign was the prime servant of the state, the great Prussian king Frederic II gave Europe one of the most significant mottos for the enlightened reform of absolutist reign towards a more modest and responsible government: not for the needs and interests of the aristocracy alone, but also for all levels of the society. According to that, also, the Habsburg empress Maria Theresia (r. 1740–65) and her son emperor Joseph II (r. 1765–90) did successfully reform the social, economic and administrative conditions in their Central European dominions, due, mainly, to a reasonable efficiency in raising wealth. An example of their endeavours can be seen in the Sugar Refinery in Rijeka, Croatia.