The Padua Circular was an attempt by Leopold, the Austrian emperor and brother of Marie Antoinette, to rally a coalition of nations for a military intervention against France:

“Plan of the Common Declaration

The undersigned are charged with making known, on the part of their sovereigns, the following…

That the effort undertaken by that prince [Louis XVI] to set himself at liberty, being most certain proof of the state of confinement in which he has found himself, no longer left any doubt that he had been forced to do violence to his religion in several respects, at the same time that the last outrage, the formal arrest of Him and of the Queen, the Dauphin, and Madame Elizabeth, inspires legitimate fears concerning the ulterior undertakings of the dominant party.

That the said sovereigns, unable to delay any longer the manifestation of sentiments and resolutions which, under the circumstances, the honour of their crowns, the ties of blood, and the maintenance of the public order and peace of Europe require of them, have ordered their undersigned ministers to declare:

That they demand that this prince and his family be set at liberty immediately, and that they claim for all said royal persons the inviolability and respect which the law of nature and of men imposes upon subjects towards their princes;

That they will unite in order to avenge in a forceful manner any future outrages which may be committed, or may be allowed to be committed, against the security, the person, and the honour of the King, the Queen and the royal family.

That, finally, they will recognise as law and as a constitution legally established in France only those [measures] which they find bearing the voluntary approval of the King, in the enjoyment of perfect liberty; but that, in the contrary case, they will employ in concert all the means within their power to bring to an end the scandal of an usurpation of power which bears the character of an open revolt, and the disastrous example of which it is important for all governments to check.

Signed in Padua,
July 5th 1791”