When was Homer's Iliad written?

This is a more complex problem than it might appear on the surface as the Iliad was originally an oral composition rather than a written text.

The war between Greece and Troy described in the epic took place roughly in the thirteenth century B.C. in an area of what would now be part of Turkey. The actual causes of the series of wars or skirmishes were probably trade disputes between the Mycenaeans (residents of the...

This is a more complex problem than it might appear on the surface as the Iliad was originally an oral composition rather than a written text.

The war between Greece and Troy described in the epic took place roughly in the thirteenth century B.C. in an area of what would now be part of Turkey. The actual causes of the series of wars or skirmishes were probably trade disputes between the Mycenaeans (residents of the Greek mainland) and the Trojans over trade and areas of naval domination.

The Iliad includes many obviously fictional elements (such as the stories of Helen and the gods, the dialogues, the story of Achilles) but also some elements of historical fact, including descriptions of geography and of material culture. In terms of linguistic elements and cultural ones, it is a hybrid, with some elements deriving from Mycenaean language and culture (such as the term wanax for leader, the use of figure-eight shaped shields) and others from archaic Greek culture. 

The story was composed, revised, and handed down orally for many centuries. It probably took something approximating its current shape in the eighth century and was first written down in the seventh century. Our earliest extant papyrus fragments of the Iliad are from the Ptolemaic period (fourth and third century BC) and thus reflect some degree of editorial intervention by Alexandrian scholars.