Many references to Solomon throughout the book confirm the claim of 1:1 that Solomon wrote this book (cf. 1:4-5, 12; 3:7, 9, 11; 6:12; 7:5; 8:11-12; 1 Kings 4:33). He reigned between 971 and 931 B.C.
How could Solomon, who had 700 wives and 300 concubines (1 Kings 11:3), be the same faithful lover this book presents? He could be if he became polygamous after the events in this book took place. That seems a more likely explanation than that he was polygamous when these events occurred but just omitted reference to his other loves. Probably he wrote the book before he became polygamous. We do not know how old Solomon was when he married the second time. The history recorded in Kings and Chronicles is not in strict chronological order. The Shulammite was probably not Pharaoh's daughter (1 Kings 3:1; cf. Song of Sol. 4:8).1
