When Haussmann created the new arrondissements for Paris with the annexion of surrounding municipalities in 1860, the idea was to have boroughts with similar population but not to enlight local identity.
Quite the opposite, places with a too strong identity (especially a left wing one) were either divided into several arrondissments or "drowned" with many other neighborhoods.
The Town hall of the arrondissment was put centrally in a neutral space.
See how the turbulent muncipality of Belleville was separated in two different arrondissement and put with other localities..
https://observatoiregrandparis.files...riquenov08.jpg
As the result what is now known as Belleville today is at the limit of 10th, 11th, 19th and 20th arrondissements.