On the 16th of November a protocol of the London conference placed the Morea, with the neighbouring islands and the Cyclades, under the guarantee of the powers; and on the 22nd of March 1829 another protocol extended the frontier thus guaranteed to the line Arta-Volo and included the island of Euboea.
Concluded, on the 27th of July, the treaty of London, whereby France, England and Russia bound themselves to put an end to the conflict in the East and to enforce the conditions of the St Petersburg protocol upon the belligerents.
Months passed without any action being taken under the protocol of the 4th of April; and Russia suspected Great Britain of merely using the protocol to prevent her Powers as own isolated intervention.
The six months that had elapsed between the signing of the peace protocol and the ratification of the treaty had constituted a virtual interregnum, Spain's authority having been practically destroyed in the Philippines and that of the United States xvii.
Already in 1884 a protocol had been signed between the contending parties, by which it was agreed that the frontier should follow the line where " the highest peaks of the Andine ranges divide the watershed."