There could be a lot of personal reasons behind Solomon’s decisions to have that many wives and concubines. However, the Bible tells us one reason why.
The widely known belief is that King Solomon wrote the book of Ecclesiastes, a manifestation of the wisdom God gave to him (1 Kings 4:29). This wisdom is described to be as vast as the sands on the Seashore. In Ecclesiastes 2, the author revealed that behind his quest to explore wisdom, he tried to experience the only happiness most people get in this life and in doing so, he collected gold and silver, and had many concubines.
Ecclesiastes 2:3 ~ After much thought, I decided to cheer myself with wine. And while still seeking wisdom, I clutched at foolishness. In this way, I tried to experience the only happiness most people find during their brief life in this world.
Ecclesiastes 2:8 ~ I collected great sums of silver and gold, the treasure of many kings and provinces. I hired wonderful singers, both men and women, and had many beautiful concubines. I had everything a man could desire!
So, it seems that in order to discover what brings true happiness, Solomon married and slept with a lot of women. Though, he stated that he found it all to be meaningless – like chasing the wind.