beginning of the end
1. The start of a decline. We didn't realize it at the time, but not having any interest in Valentine's Day was the beginning of the end for us—we broke up a month later. We all rushed to grandpa's bedside after his nurse warned us that it was the beginning of the end.
2. The first in a series of closing events. Senior prom is really the beginning of the end—graduation isn't that far away anymore.
beginning of the end, the
The start of a bad outcome (ruin, disaster, catastrophe, death), as in Joe's failing two of his courses was the beginning of the end; he dropped out soon afterward . This phrase, at first (16th century) used only to describe an approaching death, gained a new meaning after the French lost the battle of Leipzig in 1813 and Talleyrand said to Napoleon, "C'est le commencement de la fin" ("It's the beginning of the end").