Lydia arose as a Neo-Hittite kingdom following the collapse of the Hittite Empire in the twelfth century BC. According to Greek sources, the original name of the Lydian kingdom was Maionia. Herodotus relates that that the "Maiones" were renamed Lydians after their king, Lydus (Greek: Λυδός), son of Attis, in the mythical epoch that preceded the rise of the Heracleid dynasty. The boundaries of historical Lydia varied across the centuries. It was first bounded by Mysia, Caria, Phrygia and coastal Ionia. Later on, the military power of Alyattes and Croesus expanded Lydia into an empire, with its capital at Sardis, which controlled all Asia Minor west of the River Halys, except Lycia. After the Persian conquest the Maeander was regarded as its southern boundary, and under Rome, Lydia comprised the country between Mysia and Caria on the one side and Phrygia and the Aegean on the other. According to Herodotus, the Lydians were the first people to introduce the use of gold and silver coins and the first to establish retail shops in permanent locations. The dating of these first stamped coins is one of the most frequently debated topics in ancient numismatics, with dates ranging from 700 BC to 550 BC, but the most commonly held view is that they were minted at or near the beginning of the reign of King Alyattes, who ruled Lydia c. 609-560 BC. Alyattes' son was Croesus (Greek: Κροῖσος, reigned 560-547 BC), who became synonymous with wealth -- thus the expression "rich as Croesus". The Lydian capital Sardis was renowned as a rich and beautiful city. Around 550 BC, near the beginning of his reign, Croesus paid for the construction of the temple of Artemis at Ephesus, which became one of the Seven Wonders of the Ancient World. Croesus is also famous for asking the Oracle at Delphi whether he should go to war against Persia. With typical ambiguity the oracle answered that if Croesus attacked the Persians, he would destroy a great empire. He went to war and was defeated in battle by Cyrus II of Persia in 546 BC, with the Lydian kingdom losing its autonomy and becoming a Persian satrapy... thus destroying his own empire.