Did Emperor Charles I abdicate on November 11 1918?

No. He very carefully did not abdicate, but in his statement (reproduced above) chose words that left open the possibility of a legal return to rule: "Ich verzichte auf jeden Anteil an den Staatsgeschäften". A translation follows; then the document rearranged so as to be readable. The second signature is Professor Lammasch, the Prime Minister.

Ever since my accession I have tried ceaselessly to lead my peoples out of the horrors of a war for whose inception I bear no trace of blame.
I have not hesitated to restore constitutional life and I have opened up for the peoples the path of their development as independent states.
Filled, now as ever, with unwavering devotion to all my peoples, I do not wish to oppose their free growth with my own person.
I recognize in advance whatever decision that German-Austria may make about its future political form.
The people, through its representatives, has taken over the government. I renounce all participation in the affairs of state.
At the same time, I relieve my Austrian Government from offlce.
May the people of German-Austria, in unity and tolerance create and strengthen the new order! The happiness of my peoples has, from the beginning, been the object of my most ardent wishes.
Only an inner peace can heal the wounds of this war.

The statement was at once made public, in a special 2-page edition of the Wiener Zeitung.