endlong

The hero goes "overthwart and endlong," just like the figures whom all readers know in Malory, and some in his originals.

From Essays in English Literature, 1780-1860 by George Saintsbury

Again did Birdalone take heart, and they hastened a long way up the stair, till Atra stayed at last at a door all done with iron, endlong and over-thwart. 

From The Water of the Wondrous Isles by William Morris

Then he rode endlong the gates of that manor nigh half-an-hour.

From Le Mort d'Arthur: Volume 1 by Sir Thomas Malory

And last, between the endlong beams I stretched Stout thongs of ox-hide, dipped in purple dye.

From The Private Papers of Henry Ryecroft by George Gissing

So Sir Percivale turned back, but Sir Launcelot rode on across and endlong in a wild forest, and held no path, but as wild adventure led him.

From Stories of King Arthur and His Knights Retold from Malory's "Morte dArthur" by U. Waldo Cutler