Do ‘und’ and ‘till’ make “until” a tautology?

The English Oxford Dictionaries’ definition of the word 'until' lists the following as its etymology:

Middle English: from Old Norse und 'as far as' + till (the sense thus duplicated)

Etymonline similarly states:

c.1200, from O.N. und "as far as, up to" (related to O.E. end; see end) + till "until, up to".

Looking at the two entries, it seems that until is made up of two roots which mean the same thing, rendering the word something of a tautology ('up to up to'). Or does it? Etymonline also states that it is related to the word end which would effectively make the etymology of until mean, 'up to the end'. This makes some sort of sense.

The OED (online), however, does not list until as being related to end. Moreover, Etymonline does not mention und in its entry for end either, which makes things a little confusing.

So, is until something of a tautology? If so, is it unique in this aspect?

Solution 1:

It may have been perceived as redundant by some in the 13th century (but I've seen no evidence of that). It's certainly not redundant now, and to impute redundancy to it is an instance of the etymological fallacy.

Since it's originally a northern term, I'd guess that it represented a conflation of the terms used by two interpenetrating speech communities, the ON and OE.

Solution 2:

Maybe this is true, but it is equally true that most English speakers don't know Old Norse, so while its etymology may be redundant, its current usage is not.