end

end the end crowns the work the fulfilment of a process is its finest and most notable part. The saying is recorded from the early 16th century, but is also found in Latin as finis coronat opus, and 15th-century French has the similar, ‘the end praises the work.’
the end justifies the means this assertion, that a good or successful result makes the doubtful methods by which it has been achieved acceptable, is often found in the negative. The saying is recorded from the late 16th century, but is found earlier in Latin, in the work of the Roman poet Ovid, ‘exitus acta probat [the outcome justifies the deeds].’
the end of civilization as we know it the complete collapse of ordered society. Supposedly a cinematic cliché, and actually used in the film Citizen Kane (1941). Often used ironically.
the end of one's tether having no patience, resources, or energy left to cope with something. The image is that of a grazing animal tethered on a rope that allows it a certain range in which to move but which at full stretch prohibits further movement.

See also all things come to an end, light at the end of the tunnel, at the end of the rainbow, the thin end of the wedge, all's well that ends well, he who wills the end at will3, world without end.