Assyria has been ruled for a century…

Nerik, a city to the north of the Hittite capitals Hattusa and Sapinuwa, had, like Hattusa, been founded by Hattic language speakers; in the Hattusa archive, tablet CTH 737 records a Hattic incantion for a festival there.

Under Hattusili I, who reigned from about 1650 BCE to around 1620 BCE, the Nesian-speaking Hittites had taken over Nerik, where they maintain a spring festival called Puruli in honor of its storm god, who is the son of Wurusemu, sun goddess of Arinna.

In it, the celebrants recites the myth of the slaying of Illuyanka.

The weather god is associated or identified with Mount Zaliyanu near Nerik, responsible for assigning rain to the city.

Under the rule of Hantili, Nerik is ruined, very possibly by the barbarian Kaskas, and …

…the Hittites have to relocate the Puruli festival to Hattusa.

The influx of Aryan Kassites from the north increasingly threatens the Babylonian Empire.

The Kassites dislodge the Amorites about 1531 BCE to become the new political masters of Babylonia.

The Kassites, who probably constitute a very small ruling class, aim to continue earlier Mesopotamian traditions as much as possible.

Like the Sumerians before them, the Kassites speak a language not related to any other (insufficiently recorded and only poorly understood by modern scholars).

Like the Hittites, Hurrians, and Mitanni, the Kassites adopt cuneiform script to write their own language.

The Babylonian Empire engages in regular trade with city-states to the west; with Babylonian officials or troops sometimes passing to Syria and Canaan, and Amorite merchants operating throughout Mesopotamia.

The Babylonian monarchy's western connections have remained strong.

An Amorite named Abi-ramu or Abram had been the father of a witness to a deed dated to the reign of Hammurabi's grandfather; Ammi-Ditana, great-grandson of Hammurabi, still titled himself "king of the land of the Amorites".

Ammi-Ditana's father and son also bear Canaanite names: Abi-Eshuh and Ammi-Saduqa (or Ammisaduqa, Ammizaduga).

Samsu-Ditana (Samsuditana) succeeds Ammi-Saduqaas king of Babylon in 1626 BCE.

The well-disciplined armies of Babylonia had conquered the city-states of Isin, Elam, and Uruk, and the strong Kingdom of Mari, and the rule of Babylon has been obeyed as far as the shores of the Mediterranean.

But Mesopotamia has no natural, defensible boundaries, making it vulnerable to attack, and the Babylonian Empire suffers increasingly from incursions by Kassites invading from the north.

Huzziya I, who succeeds Hittite king Ammunu in about 1530, may be his son; he rules for about five years.

By the time his successor, Telepinu, ascends throne in about 1525, the Hittite Empire has contracted to its core territories, having long since lost all of its conquests made in former times under Hattusili I and Mursili I—to Arzawa in the West, Mitanni in the East, the Kaskas in the North, and Kizzuwatna in the South.

Mursili I plunders Babylon around 1531 BCE, leaving it to the further depredations of the Kassites and other groups of which little is known, notably the Dynasty of the Sealand, based in the far south, who fill the power vacuum left when the Hittites withdraw.

Mursili defeats the Hurrians on his return march from Babylon, bringing with him captives and possessions of Babylon to Hattusa.

Following the death of Mursili in 1526 BCE, the Hittite kingdom will experience several decades of internal strife, punctuated by political insurrection, royal assassinations, and palace intrigues.

As a result of the ongoing chaos, the Hittites will lose control of much of their previously acquired territory in Anatolia and Syria.

The culture of Avaris, which has become a huge city, is overwhelmingly Canaanite by the time of Egypt's Fifteenth Dynasty, as the reign of Hyksos kings is known, evincing a long and gradual development of Canaanite power in the delta, and a peaceful takeover of power there.

The Hyksos traditionally also form the sixteenth dynasty, although those rulers are probably only vassals of the fifteenth dynasty kings.

Avaris, which becomes the Hyksos capital about 1530, is sacked nine years later by Ahmose, the victorious founder of the native Eighteenth Dynasty who completes the war of liberation begun by his kinsman Kamose.

Having expelled the Hyksos, Ahmose institutes the New Kingdom policy of conquest in Palestine and Syria.

The once-great Delta city of Avaris fades into obscurity, and the towns of Canaan are on the defensive.

The Kassites who now rule Babylonia aim to continue earlier Mesopotamian traditions as much as possible.

The heliacal rising of Sothis, a dating of the reign of Amenhotep I, followed by that of Thutmose I, occurs in 1517 BCE.

The element mercury, one of the first metals known, has been discovered in Egyptian tombs dating from this decade.