From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Lacedaemo'nians. In Greece, The Inhabitants Of Lacedaemon Or Sparta, with whom the Jews claimed kindred.  2 Maccabees 12:2;  1 Maccabees 12:5-6;  1 Maccabees 12:20-21;  1 Maccabees 14:20;  1 Maccabees 14:23;  1 Maccabees 15:23;  2 Maccabees 5:9.

Hastings' Dictionary of the Bible [2]

LACEDÆMONIANS . In 2Ma 5:9 we read that Jason fled for refuge to the Lacedæmonians ‘because they were near of kin.’ This claim is further set forth in 1Ma 12:2 ff; cf. 1Ma 14:16; cf. 1Ma 14:20 f., 1Ma 15:23 , where we read of Sparta and an alliance with the Spartans . It was, of course, entirely fanciful, the Hellenes and the Jews belonging respectively to the Indo-European and Semitic branches of the human race.

A. E. Hillard.

International Standard Bible Encyclopedia [3]

las - - dḗ - mō´ni - anz ( Σπαρτιᾶται , Spartiátai  ; once only Λακεδαιμόνιοι , Lakedaimónioi ,   2 Maccabees 5:9 ): The inhabitants of Sparta or Lacedaemon with whom the Jews claimed some kinship and formed alliances ( 1 Maccabees 12:2,5 ,  6,20 ,  21;  14:20,23;  15:23;  2 Maccabees 5:9 ). The alliance mentioned in  1 Maccabees 12:5-23 is based, among other grounds, on that of a common descent of Jews and Lacedaemonians from Abraham, for which the only probable presumption - suggested by Ewald - is the similarity of names, "Pelasgi" and Peleg son of EberGenesis 10:25;  Genesis 11:16 ). This has been reasonably objected to, and perhaps the most that can be said on this point is that the belief in some relationship between the Jews and the Lacedaemonians seems to have prevailed when 1 Macc was written. The alliance itself is said to have been formed (1 Macc 12:20) between Areus, king of the Lacedaemonians and Onias the high priest; but it is not easy to make out a consistent chronology for the transaction. For the renewal of the alliance (circa 144 BC) by Jonathan (1 Macc 12:5-18) and again by Simon (1 Macc 14:16-23), something can be said, as the Greeks had finally been deprived of independence in 146 BC, and Sparta was only obliged to lend assistance to Rome and may be supposed to have been doing so in helping the Jews against Syria. It is possible, too, that as against Syrian Hellenism the Jews were anxious to show that they had the assistance of distinguished Greeks, though the actual power of Sparta was much reduced from that of former times. The facts, at least of the alliance and the correspondence, seem to be sufficiently attested, though it is not easy to reconcile all the particulars. Josephus ( Ant. , Xii , iv, 10; Xiii , v, 8; Xiv , xii, 2, 3) gives the correspondence at greater length than the writer of the Maccabees.