The Psalms of Solomon were referenced in Early Christian writings, but lost to modern scholars until a Greek manuscript was rediscovered in the 17th century. There are currently eight known 11th to 15th century manuscripts of a Greek translation from a lost Hebrew or Aramaic original, probably dating from the first or second century BCE. However, though now a collection, they were originally separate, written by different people in different periods.
Politically, the Psalms of Solomon are anti-Maccabee, and some psalms in the collection show a clear awareness of the Roman conquest of Jerusalem under Pompey in 63 BCE, metaphorically treating him as a dragon who had been sent by God to punish the Maccabees. Some of the psalms are messianic, in the Jewish sense (clearly referring to a mortal that happens to be divinely assisted, much like Moses), but the majority are concerned less with the world at large, and more with individual behaviour, expressing a belief that repentance for unintended sins will return them to God's favour.
There have been attempts to link the text both to the Essenes of Qumran, who separated themselves from what they saw as a wicked world, and alternately to the Pharisees in opposition to the Sadducees who generally supported the Maccabees.