Georges Roux, in his book Ancient Iraq (Third edition, p. 68), says that
The city of Uruk was born of the coalescence of two towns 800 metres apart: Kullaba, devoted to the sky-god An (or Anu), the supreme god of the Mesopotamians, and E-Anna ('House of Heaven'), the main abode of the love goddess Inanna (called Ishtar by the Semites).
Is this the first historical example of conurbation? (For those of you who don't know, conurbation is the process of physical coalescence of cities)