(Θεσσαλονίκη), a Macedonian princess, was a daughter of Philip, son of Amyntas, by his wife or concubine, Nicesipolis of Pherae. (Athen. 13.557c.; Paus. 9.7.3.)
Thessalonice appears to have been brought up by her stepmother Olympias, to whose fortunes she attached herself when the latter returned to Macedonia in B. C. 317, and with whom she took refuge in the fortress of Pydna, on the advance of Cassander. (Diod. 19.35; Just. 14.6.) The fall of Pydna threw her into the power of Cassander, who embraced the opportunity to connect himself with the ancient royal house of Macedonia by marrying her; and he appears to have studiously treated her with the respect due to her illustrious birth. This may have been as much owing to policy as to affection : but the marriage appears to have been a prosperous one; she became the mother of three sons, Philip, Antipater, and Alexander; and her husband paid her the honour of conferring her name upon the city of Thessalonice, which he founded on the site of the ancient Therma, and which soon became, as it continues down to the present day, one of the most wealthy and populous cities of Macedonia. (Diod. 19.52; Paus. 8.7.7; Strab. vii. fr. 24, p. 81, ed. Kramer; Steph. Byz. s. v. Θεσσαλονίκη.) After the death of Cassander, Thessalonice appears to have at first retained much influence over her sons, but at length Antipater, becoming jealous of the superior favour which she showed to his younger brother Alexander, barbarously put his mother to death, B. C. 295. (Paus. 9.7.3; Diod. xxi. Exc. Hoesch. p. 490.)
[E.H.B]