What does the phrase 'for dear life' (for example as in, He ran for dear life) originate from? And when was it first used and became popular?
The American Heritage Dictionary of Idioms dates for dear life to the mid-1800s, although that appears to be too late by a wide margin, as I find a use from an 1815 stage play with unquestionably the same meaning as today:
Hold thee tongue: here be datur Fanny, sir, after you and Mr. Perry went away, comed runnin for dear life, and axed for Mr. Perry and when I told her he were gone, she falled down on the floor and then, sir, I picked her up in my arms, and she ha'nt spoke since.
It seems clear that for dear life was a fairly well recognized idiom by the time this play was published. I found some even earlier uses, but they mostly seem to be less idiomatic and more literal.
A Google Books search turns up instances of the phrase going back to 1749. Interestingly, though the first occurrence is in a polemical discourse addressing religious disputation, the next two are in stage scripts in which the person who says "for dear life" appears to be an uneducated countryperson. This suggests an association (during the eighteenth century) of the phrase with common folk. Here are the first three Google Books matches.
From an anonymous author, "A Discourse on Government and Religion" (1749), reprinted in The Pillars of Priestcraft and Orthodoxy Shaken, volume 3 (1768):
The Presbyterians indeed pulled down the common prayer, because God should not be on the side of the church ; for if they did not pray, to be sure the Lord could not hear them, and they could not pray without book, at the same time the presbyterians themselves pray'd for dear life—and liberty to pray.
From Isaac Bickerstaff, Love in a Village ; a Comic Opera (1762):
Hodge [a servant]. Lord, your honour, look out, and see what a nice show they make yonder ; they had got pipers and fidlers, and were dancing as l came along, for dear life —I never saw such a mortal throng in our village in all my born days again.
From Sophia Lee, The Chapter of Accidents (1780):
Bridget [maid to another character]. So he axed for my Lady, and would not tell me what he wanted : I came with her, however, but she no sooner set eyes on him than she sent me out ; and before I could possibly get back, though I ran as fast as ever my legs could carry me, he was gone, and she writing and crying for dear life ;---but that was no news, so I did not mind it : and when she gave me leave to go to the play, thought no more harm than the child unborn.
Several decades later, the phrase also appears twice in Walter Scott, Redgauntlet (1824), once each by the two characters whose epistles make up much of the early part of the novel:
[from Letter 5, Alan Fairford to Darsie Latimer] I admire the figure which thou must have made, clinging for dear life behind the old fellow's back—thy jaws chattering with fear, thy muscles cramped with anxiety.
[from Letter 11, Darsie Latimer to Alan Fairford] You are now to conceive us proceeding in our different directions across the bare downs. Yonder flies little Benjie to the northward, with Hemp scampering at his heels, both running as if for dear life, so long as the rogue is within sight of his employer, and certain to take the walk very easy, so soon as he is out of ken.
In Redgauntlet, Scott does not seem to be using the phrase as a social-class marker for the characters who employ it in their letters.