The Medes, or Medians, were a group of early Iranian tribes who united under King Cyaxares (624–585 BCE) and formed an alliance with the Babylonians under King Nabopolassar against the Neo-Assyrians, who at the time ruled most of the Near East. Assyrian fragmentation led to their loss of the cities of Nineveh (612) and Harran (610) and enabled the Medians to extend their control westwards as far as Anatolia. The Lydians under King Alyattes, ruling from Sardis, agreed a truce with the Medians in 584 and arranged the intermarriage of their royal houses, ensuring a period of stability and prosperity. Alyattes also took control of the Greek towns on the Mediterranean cost, and is credited with being the first ruler in the world to introduce a system of coinage. He was succeeded in 560 by his grandson Croesus, who was to become famously rich. The Chaldeans were a Semitic people who from the 9th century had spread up from the marshlands of southern Mesopotamia and who briefly ruled Babylonia. Egypt was under the rule of the 26th Dynasty, founded by Psamtik I in 656 BCE, and called ‘Saite’ after their capital at Sais. Egyptian power was in decline and this last native Egyptian dynasty fell to the Achaemenid Persians in 525 BCE.