This Mises Daily article argues that the Levellers, who predated Locke by about a century, where the originators of classical liberalism.
It quotes Rothbard as saying:
[i]n a series of notable debates within the Republican Army — notably
between the Cromwellians and the Levellers — the Levellers led by John
Lilburne, Richard Overton and William Walwyn, worked out a remarkably
consistent libertarian doctrine, upholding the rights of
self-ownership, private property, religious freedom for the
individual, and minimal government interference in society. The rights
of each individual to his person and property, furthermore, were
natural, that is, they were derived from the nature of man (1).
If they had developed the concept of self-ownership, this could be considered almost equivalent with having developed the NAP. To quote Wikipedia:
Specifically, any unsolicited actions of others that physically affect
an individual’s property or person, no matter if the result of those
actions is damaging, beneficial, or neutral to the owner, are
considered violent or aggressive when they are against the owner's
free will and interfere with his right to self-determination and the
principle of self-ownership.
- M. N. Rothbard, An Austrian Perspective on the History of Economic Thought, Cheltenham, Edward Elgar, 1995, vol. I, p. 313
Citation for Rothbard quote retrieved from this article with the same quote: https://mises.org/daily/6704/Englands-Levellers-The-Worlds-First-Libertarian-Movement (Yes, I'm citing the source of my citation. :)