pronouns - Why are "he", "she", and "it" distinct in the singular, but all "they" in the plural?

Other languages have gender-specific third-person plural pronouns (e.g., ellos and ellas in Spanish). English does not, despite the masculine/feminine/neuter distinction being obligatory in the singular.

Is there a historical reason for this situation? Was there a time when English had gendered versions of "they"?

Answer

Old English not only had many plural personal pronouns, but it also distinguished between the nominative, accusative, dative, and genitive cases. See Wikipedia.

By about 1400 they (which was originally a masculine plural demonstrative pronoun borrowed from Old Norse) gradually replaced these personal pronouns.