Esth 1:2

“That in those days, when the King Ahasuerus sat on the throne of his kingdom,.... Not only was placed upon it, but settled in it; after Xerxes had subdued Egypt, in the second year of his reign (e), and enjoyed great peace and tranquillity: which was in Shushan the palace; that is, the throne of his kingdom was in Shushan, the royal city of the kings of Persia; of which see Gill on Neh 1:1, Dan 8:2. (e) Herodot. ib. (Thalia, sive, l. 3.) c. 7.”

“Sat on the throne of his kingdom - Having subdued all his enemies, and brought universal peace to his empire. See the commencement of the introduction. Shushan the palace - The ancient city of Susa, now called Shuster by the Persians. This, with Ecbatana and Babylon, was a residence of the Persian kings. The word הבירה habbirah, which we render the palace, should be rendered the city, εν Σουσοις τῃ πολει, as in the Septuagint.”

“Captial. Hebrew, “palace, (Protestants; Haydock) or castle,” (Calmet) may also signify “a capital.” (Montanus, &c.) — Hystaspes founded this ancient royal city of Persia, (Pliny, [Natural History?] vi. 27.) or he greatly embellished it. (Calmet) (Ælian, Anim. xiii. 18.) (Tirinus) — He seems to have resided here almost constantly. The preceding kings (Calmet) spent the winter in this warm climate, and perhaps the spring. See 2 Esdras i. 1. They spent other parts of the year at Ecbatana and at Babylon. (Calmet)”