is "SIR" came from the word "SIRE"?

Answer 1

Etymology says this:

sir
1297, title of honor of a knight or baronet (until 17c. also a title of priests), variant of sire, originally used only in unstressed position. Generalized as a respectful form of address by c.1350; used as a salutation at the beginning of letters from 1425.

Looking under SIRE, it says:
sire
c.1205, title placed before a name and denoting knighthood, from O.Fr. sire, from V.L. *seior, from L. senior "older, elder" (see senior). Standing alone and meaning "your majesty" it is attested from c.1225. General sense of "important elderly man" is from 1362; that of "father, male parent" is from c.1250. The verb meaning "to beget, to be the sire of" is attested from 1611, from the noun.

Answer 2

As a term of polite address to a man the word 'sir' comes from 'sire' My dictionary gives it as a 13th century variant.