The order of the boot
Given the sack, i.e. asked to leave your job (see 'get the sack').
A jokey version of 'kicked out' or 'booted out'. It also conjures up ironic images of real heraldic orders like the Order of the Garter.
The first record of 'given the boot' in print is in Sir H. Rider Haggard's Colonel Quaritch, 1888:
"Well, it's a good job anyway, and I thank God Almighty for it," said he, "and more especial since there'll be the money to take over the Moat Farm and give that varmint Janter the boot."
"Give him what?"
"Why, kick him out, sir, for good and all, begging your pardon, sir."
Slightly later, as you might expect, is the first reference to 'the order of the boot', in Henry Taprell Dorling's (a.k.a. Taffrail) The Sub:
"An habitual slacker... generally got the Order of the Boot at the end of his third term."