Complex sentence: On 21 May 1790, the Charter of the city of Paris was adopted, declaring the city independent of royal authority: it was divided into twelve municipalities, (later known as "arrondissements"), and into forty-eight sections.
Split into simpler sentences: On 21 May 1790, the Charter of the city of Paris was adopted, declaring the city independent of royal authority. The city was divided into twelve municipalities, (later known as "arrondissements"), and into forty-eight sections.