Difference between Illegitimacy and Bastardy

What is the difference between Illegitimacy and Bastardy?

Illegitimacy as a noun is the state or condition of being illegitimate while Bastardy as a noun is the condition of being illegitimate, of being born to an unmarried woman or as the fruit of adultery.

We hope you now know whether to use Illegitimacy or Bastardy in your sentence.