George a Green is also known as the "Pindar of Wakefield" (pindar could also be spelled pinder or pinner). The book The History of George a Green; Pindar of the Town of Wakefield, published in 1827 (and available on Archive.org) reprinted a ballad that contains a precursor of "None shall pass" from Monty Python and the Holy Grail:
In Wakefield there lives a jolly pinder,
In Wakefield, all on a green
In Wakefield, all on a green;
There is neither knight nor squire, said the pinder,
Nor baron so bold,
Nor baron so bold,
Dare make a trespas to the town of Wakefield,
But his pledge goes to the pinfold, &c.
All this be heard three witty young men,
Twas Robin Hood, Scarlet, and John;
With that they espy'd the jolly pinder
As he sat under a thorn.
Now turn again, turn again, said the pinder,
For a wrong way you have gone,
For you have forsaken the kings highway,
And made a path over the corn.
[The pinder] leaned his back fast unto a thorn,
And his foot against a stone,
And there he fought a long summers day,
A summers day so long,
Till that their swords on their broad bucklers,
Were broke fast into their hands.
Hold thy hand, hold thy hand said bold Robin Hood,
And my merry men every one;
For this is one of the best pinders,
That ever I tryed with sword
(For a full version with some annotations, see the Robbins Library Digital Projects at the University of Rochester.)
The anonymous editor of the above-mentioned volume adds (emphasis mine),
This it will be perceived is the incident described in the tenth chapter of the present work, and for the valour displayed by the Pinder, upon this and all similar occasions, his name has passed into a proverb, and "as good as George A Green," is a saying in use even at the present time.
A play entitled George a Greene was performed in December 1593 and January 1594 (according to Henslowe's "diary"); one of the three companies that performed it was the Lord Chamberlain's Men, of which Shakespeare was a member. According to the Folger Shakespeare Library, the play was first performed in 1590. A Pleasant Conceyted Comedie of George a Greene, the Pinner of Wakefield was printed in 1599.