How many mistresses did Solomon actually have? As read here, it says, in 1st Kings, 11:3, "And he had seven hundred wives, princesses, and three hundred concubines: and his wives turned away his heart." This is speaking of King Solomon. My confusion: are the concubine and princesses included in the 700, or separately, and if so, how many did they account for? I am simply having issues understanding the verse's wording.
Compare a number of English versions here. Nearly all have the form 700 and 300. The Bible in Basic English (BBE) specifically reads,


  He had seven hundred wives, daughters of kings, and three hundred other wives; and through his wives his heart was turned away.


There is no real reason to think the numbers don't add together to make 1000 total, and in fact the "1000 wives" of Solomon are considered by some commentators to be an illustration of the bride of Christ. The 700 wives are royalty, so considered an equal match for Solomon to marry. The other 300 presumably were commoners, so had lower social status and were called "concubines" instead of wives.