Coins from Lydian Kingdom
Lydia developed after the decline of the Hittite Empire in the 12th century BC. In Hittite times, the name for the region had been Arzawa. According to Herodotus, Lydia was ruled by three dynasties from the second millennium BC to 546 BC. The first two dynasties are legendary and the third is historical.

According to Herodotus, the Lydians were the first people to use gold and silver coins and the first to establish retail shops in permanent locations. It is not known, however, whether Herodotus meant that the Lydians were the first to use coins of pure gold and pure silver or the first precious metal coins in general. Despite this ambiguity, this statement of Herodotus is one of the pieces of evidence most often cited on behalf of the argument that Lydians invented coinage, at least in the West, although though the first coins (under Alyattes I, reigned c.591–c.560 BC) were neither gold nor silver but an alloy of the two called electrum.

In 547 BC, the Lydian king Croesus besieged and captured the Persian city of Pteria in Cappadocia and enslaved its inhabitants. The Persian king Cyrus The Great marched with his army against the Lydians. The Battle of Pteria resulted in a stalemate, forcing the Lydians to retreat to their capital city of Sardis. Some months later the Persian and Lydian kings met at the Battle of Thymbra. Cyrus won and captured the capital city of Sardis by 546 BC. Lydia became a province (satrapy) of the Persian Empire.

The expression "rich as Croesus" refers to this king.
Lydian Kingdom
Alyattes was the fourth king of the Mermnad dynasty in Lydia, the son of Sadyattes and grandson of Ardys. He was succeeded by his son Croesus.

A battle between his forces and those of Cyaxares, king of Media, was interrupted by the solar eclipse on 28 May 585 BC. After this, a truce was agreed and Alyattes married his daughter Aryenis to Astyages, the son of Cyaxares. The alliance pres...
Reportedly, Croesus on the death of his father Alyattes faced a rival claimant to the throne in Pantaleon, son of Alyattes by a different mother. Croesus prevailed, and a number of the opposite faction were executed, and their property confiscated. As soon as his reign was secure, Croesus continued his sires' wars against the Asian Greeks, bringing all the Aeolian and Ionian Settlements on the coa...