Maybe it's worth pointing out that the meaning of municipiu differs from municipality in other countries: It means a Romanian town of a certain size and importance. Small towns are not a municipiu; 13 big metropolises, such as Cluj-Napoca and Timișoara, are municipiu de rangul 1 (first-class municipality), smaller but still important ones are "rang 2". București, the capital, sometimes is said to be "rang 0".
With this knowledge I think the sentence is easier to understand.
Thanks to Renardo and Gustawsohn, really helpful and the literal translation is meaningless. In England we have some towns and cities that are "unitary authorities" meaning they are not beneath / subservient administratively to counties - that is probably the closest to the meaning as I now understand it.
That is a good question. Sorin Paliga [http://cejsh.icm.edu.pl/cejsh/element/bwmeta1.element.ojs-doi-10_11649_sm_2015_005/c/sm.2015.005-1410.pdf] mentions that he refuted the hypothesis about the hungarian "város" (city); instead he claims Thracian origin, as there are Thracian "place‐names ending in ‐ora, ‐oros, ‐oron". Through this Thracian root the term is related to the Latin "urbs" (city) and "orbis" (world, Earth).