Attalus I. was the son of Attalus, the brother of Philetaerus, and Antiochis, daughter of Achaeus (not the cousin of Antiochus the Great). [EUMENES.] He succeeded his cousin, Eumenes I., in B. C. 241.
He was the first of the Asiatic princes who ventured to make head against the Gauls, over whom he gained a decisive victory.
After this success, he assumed the title of king (Strab. xiii. p.624
; Paus. 1.8.1
; Liv. 38.16
; Plb. 18.24
), and dedicated a sculptured representation of his victory in the Acropolis at Athens. (Paus. 1.25.2
He took advantage of the disputes in the family of the Seleucidae, and in B. C. 229 conquered Antiochus Hierax in several battles. (Porphyr. apud Euseb. Graec.
p. 186; Euseb. Chron. Arm.
Before the accession of Seleucus Ceraunus (B. C. 226), he had made himself master of the whole of Asia Minor west of mount Taurus. Seleucus immediately attacked him, and by B. C. 221 Achaeus [ACHAEUS] had reduced his dominions to the limits of Pergamus itself. (Plb. 4.48
On the breaking out of the war between the Rhodians and Byzantines (B. C. 220), Attalus took part with the latter, who had done their utmost to bring about a peace between him and Achaeus (Plb. 4.49
), but he was unable to render them any effective assistance. In B. C. 218, with the aid of a body of Gaulish mercenaries, he recovered several cities in Aeolis and the neighbouring districts, but was stopped in the midst of his successes by an eclipse of the sun, which so alarmed the Gauls, that they refused to proceed. (Plb. 5.77
.) In B. C. 216, he entered into an alliance with Antiochus the Great against Achaeus. (5.107.) In B. C. 211, he joined the alliance of the Romans and Aetolians against Philip and the Achaeans. (Liv. 26.24
.) In 209, he was made praetor of the Aetolians conjointly with Pyrrhias, and in the following year joined Sulpicius with a fleet.
After wintering at Aegina, in 207 he overran Peparethus, assisted in the capture of Oreus, and took Opus. While engaged in collecting tribute in the neighbourhood of this town, he narrowly escaped falling into Philip's hands; and hearing that Prusias, king of Bithynia, had invaded Pergamus, he returned to Asia. (Liv. 27.29
; Plb. 10.41
In B. C. 205, in obedience to an injunction of the Sibylline books, the Romans sent an embassy to Asia to bring away the Idaean Mother from Pessinus in Phrygia. Attains received them graciously and assisted them in procuring the black stone which was the symbol of the goddess. (Liv. 29.10
At the general peace brought about in 204, Prusias and Attalus were included, the former as the ally of Philip, the latter as the ally of the Romans. (29.12.) On the breaking out of hostilities between Philip and the Rhodians, Attalus took part with the latter; and in B. C. 201, Philip invaded and ravaged his territories, but was unable to take the city of Pergamus.
A sea-fight ensued, off Chios, between the fleet of Philip and the combined fleets of Attalus and the Rhodians, in which Philip was in fact defeated with considerable loss, though he found a pretext for claiming a victory, because Attalus, having incautiously pursued a Macedonian vessel too far, was compelled to abandon his own, and make his escape by land.
After another ineffectual attempt upon Pergamus, Philip retired. (Plb. 16.1
; Liv. 32.33
In 200, Attalus, at the invitation of the Athenians, crossed over to Athens, where the most flattering honours were paid him.
A new tribe was created and named Attalis after him. At Athens he met a Roman embassy, and war was formally declared against Philip. (Plb. 16.25
; Liv. 31.14
; Paus. 1.5.5
In the same year, Attalus made some ineffectual attempts; to relieve Abydos, which was besieged by Philip. (Plb. 16.25
In the campaign of 199, he joined the Romans with a fleet and troops. Their combined forces took Oreus in Euboea. (Liv. 31.44
.) Attalus then returned to Asia to repel the aggressions of Antiochus III., who had taken the opportunity of his absence to attack Pergamus, but was induced to desist by the remonstrances of the Romans. (Liv. 31.45
In 198, Attalus again joined the Romans, and, after the campaign, wintered in Aegina.
In the spring of 197, he attended an assembly held at Thebes for the purpose of detaching the Boeotians from the cause of Philip, and in the midst of his speech was struck with apoplexy.
He was conveyed to Pergamus, and died the same year, in the seventy-second year of his age, after a reign of forty-four years. (Liv. 32.16
; Plb. 17.2
As a ruler, his conduct was marked by wisdom and justice; he was a faithful ally, a generous friend, and an affectionate husband and father.
He encouraged the arts and sciences. (D. L. 4.8
; Athen. 15.697
; Plin. Nat. 8.74
By his wife, Apollonias or Apollonis, he had four sons: Eumenes, who succeeded him, Attalus, Philetaerus, and Athenaeus.