Alyattes (Ancient Greek: Ἀλυάττης Aluáttēs, likely from Lydian Walwates; reigned c. 618–561 BC), sometimes described as Alyattes I, was the fourth king of the Mermnad dynasty in Lydia, the son of Sadyattes and grandson of Ardys. He died after a reign of 57 years and was succeeded by his son Croesus. A battle between his forces and those of Cyaxares, king of Media, was interrupted by the solar eclipse of 28 May 585 BC. After this, a truce was agreed and Alyattes married his daughter Aryenis to Astyages, the son of Cyaxares. The alliance preserved Lydia for another generation, during which it enjoyed its most brilliant period. Alyattes continued to wage a war against Miletus for many years but eventually he heeded the Delphic Oracle and rebuilt a temple, dedicated to Athena, which his soldie