Despite praise for levirate marriage, it was almost completely abandoned by the end of the second century C.E. as it often clashed with the move toward monogyny.    From Wordnik.com.  [Post-Biblical and Rabbinic Women.] Reference

However, internal developments, as well as the influence of the western civilizations under whose aegis the Jews had come beginning with the third century B.C.E. (the Greeks and then the Romans), tended toward monogyny and dowry marriages.    From Wordnik.com.  [Post-Biblical and Rabbinic Women.] Reference