Were the vows of the Night's Watch the same from the beginning?

One of the vows of the Night's Watch say that they must stay celibate.

We do know though, that the Brothers do go to brothels near the Wall, but none of them take any wives.

On reading the World of Ice and Fire, I found out about a legend that there was a Lord Commander (the 13th) that took a wife.

The exact quote is:

[...] The oldest of these tales concern the legendary Night's King, who was alleged to have bedded a sorceress pale as a corpse and declared himself a king. For thirteen year the Night's King and his 'corpse queen' ruled together [...]

_{page 145}

_{So, I was wondering: Were the vows of the Night's Watch the same from the beginning?}

_{It is clearly said that the aforementioned story is only a legend, so we don't know for sure if it is true or not, but could it have been the case that when the Night's Watch first started, the Brothers could marry?}

_{The Night's King was defeated by the Starks after 13 years.}