Old - About fifty or fifty-five. From his age at his accession (1 Kings 2:2 note) he could not have been more than about sixty at his death.
The true nature of Solomon’s idolatry was neither complete apostasy - an apostasy from which there could be no recovery; nor a mere toleration, rather praise-worthy than blameable. Solomon did not ever openly or wholly apostatize. He continued his attendance on the worship of Yahweh, and punctually made his offerings three times a year in the temple 1 Kings 9:25; but his heart was not “perfect” with God. The religious earnestness of his younger days was weakened by wealth, luxury, sensualism, an increasing worldliness leading him to worldly policy and latitudinarianism arising from contact with all the manifold forms of human opinion. His lapse into deadly sin was no doubt gradual. Partly from ostentation, partly from that sensualism which is the most common failing of Oriental monarchs, he established a harem on a grand and extraordinary scale. To gratify “strange women,” i. e., foreigners, admitted either from worldly policy, or for variety’s sake, he built magnificent temples to their false gods, right over against Jerusalem, as manifest rivals to “the temple.” He thus became the author of a syncretism, which sought to blend together the worship of Yahweh and the worship of idols - a syncretism which possessed fatal attractions for the Jewish nation. Finally, he appears himself to have frequented the idol temples 1 Kings 11:5, 1 Kings 11:10, and to have taken part in those fearful impurities which constituted the worst horror of the idolatrous systems, thus practically apostatising, though theoretically he never ceased to hold that Yahweh was the true God.