When the Babylonians took over Mesopotamia around 1900 BC, the astronomical research intensified. From this era we have the world's oldest known astrological text: the Venus Tablet of Ammisaduqa, dating from around the 17th century BC.
It is a systematic compilation of omens drawn from the dates on which Venus first and last appeared above the horizon over the course of 21 years. The text contains predictions about floods, the availability of food, the outcomes of wars and so on. For example: 'In month Arahsamna, 11th day, Venus disappeared in the east. Two months ... days it stayed away in the sky. In month Tebeti, ...th day, Venus became visible in the west: the harvest of the land will prosper.'
"The Great World History Book"