Albeit

google

ref

late Middle English: from the phrase all be it ‘although it be (that’).

wiktionary

ref

From the Middle English expression al be it ( that), itself shortened from althagh it be that(“although it be that”), and thus composed from al(“completely, entirely”) +‎ be(3rd person singular present subjunctive of been(“to be”)) +‎ it.

etymonline

ref

albeit (conj.)

late 14c., a contraction of al be it "al(though) it be (that);" see all be it. Chaucer also uses a past-tense form, al were it.