Natheless, [nevertheless] it was I who did educate Miss Lucy in all useful learning.
-- Sir Walter Scott, Guy Mannering
Natheless, God send you good success, and to that end will we pray.
-- Mark Twain, A Connecticut Yankee in King Arthur's Court.
Origin:
Natheless is an Old English word. Nā meant "not" in Old English, and the other roots ( the and less ) have remained constant in modern English.

"No more," quoth she, "by God ye have enough;"
And wantonly again with him she play'd,
Till at the last this merchant to her said.
"By God," quoth he, "I am a little wroth
With you, my wife, although it be me loth;
And wot ye why? by God, as that I guess,
That ye have made a manner strangeness
Betwixte me and my cousin, Dan John.
Ye should have warned me, ere I had gone,
That he you had a hundred frankes paid
By ready token; he had him evil apaid
For that I to him spake of chevisance,
(He seemed so as by his countenance);
But natheless, by God of heaven king,
I thoughte not to ask of him no thing.
I pray thee, wife, do thou no more so.
Tell me alway, ere that I from thee go,
If any debtor hath in mine absence
Y-payed thee, lest through thy negligence
I might him ask a thing that he hath paid."
~ Geoffrey Chaucer, The Shipman's Tale

To the dim light and the large circle of shade.
I have clomb, and to the whitening of the hills;.
There where we see no colour in the grass.
Nathless my longing loses not its green,
It has so taken root in the hard stone.
Which talks and hears as though it were a lady...
~Dante Gabriel Rossetti, Of the Lady Pietra degli Scrovigni

Natheless the chiefs drove a handsome trade in thus disposing of their surplus live meat.
~ Jack London, South Sea Tales

And if he doth not return, this Wilfred may natheless repay us our charges when he shall gain treasure by the strength of his spear and of his sword, even as he did yesterday and this day also.
~ Walter Scott, Ivanhoe



********