Dagon - (Dagan) a god of Syria-Mesopotamia, later of the Canaanites, and finally of the Philistines. Very little is known about either his origins or exact nature. By most evidence Dagan was a pre-Sumerian, pre-Semite god worshiped in the middle Euphrates region. There were important shrines of Dagan at Tuttul, Mari, and Terqa, all within present-day Syria. With the emergence of the empire of Akkad under Sagan (c. 2300 BCE), Dagan was adopted as an Akkadian national god. During the following period of neo-Sumerian renaissance (Ur III, c. 2100-2000 BCE), Dagan's name is found on seals alongside that of his consort, Shalash, a goddess of perhaps Hurrian origin. She may be the same as Shala, the consort of the Babylonian weather god Adad. In the Isin-Larsa period (C. 2000-1900 BCE) two kings of Isin bear names with the element dagan, Indindagan ("Dagan has given") and Ishmedagan ("Dagan has heard").
No doubt Dagan had a significant function among the Canaanites, but few sources provide real evidence of his role. Baal is called "son of Dagan". Several towns within Canaanite territory are named Bet-Dagan ("temple of Dagan").
Dagan was the chief god of the Philistines, who surely borrowed his cult from the Canaanites.
Dagan was most likely a god of good weather and agricultural fertility.
Encyclopedia of Religion, Eliade, M., ed., NY, 1987, V.4, p. 196