The military situation now required a prompt retirement beyond the
Moselle. The southerly line of retreat, which MacMahon and de Failly had
been driven to take, forbade the hope of their junction with the main
army at Metz in time to oppose a united front to the enemy. And it was
soon known that their flight could not be stayed at Nancy or even at
Toul. During the agony of suspense as to their movements and those of
their German pursuers, the Emperor daily changed his plans. First, he
and Leboeuf planned a retreat beyond the Moselle and Meuse; next,
political considerations bade them stand firm on the banks of the Nied,
some twelve miles east of Metz; and when this position seemed unsafe,
they ended the marchings and counter-marchings of their troops by taking
up a position at Colombey, nearer to Metz.

Meanwhile at Paris the Chamber of Deputies had overthrown the Ollivier
Ministry, and the Empress-Regent installed in office Count Palikao.
There was a general outcry against Leboeuf, and on the 12th the Emperor
resigned the command to Marshal Bazaine (Lebrun now acting as Chief of
Staff), with the injunction to retreat westwards to Verdun. For the
Emperor to order such a retreat in his own name was thought to be
inopportune. Bazaine was a convenient scapegoat, and he himself knew it.
Had he thrown an army corps into Metz and obeyed the Emperor's orders by
retreating on Verdun, things would certainly have gone better than was
now to be the case. In his printed defence Bazaine has urged that the
army had not enough provisions for the march, and, further, that the
outlying forts of Metz were not yet ready to withstand a siege--a
circumstance which, if true, partly explains Bazaine's reluctance to
leave the "virgin city[40]." Napoleon III. quitted it early on the 16th:
he and his escort were the last Frenchmen to get free of that death-trap
for many a week.