London Protocol is a name used to describe several different documents.
On 21 June 1814, a secret convention between the Great Powers: United Kingdom of Great Britain and Ireland, Prussia, Austria, and Russia awarded the territory of current Belgium and the Netherlands to William I of the Netherlands, then "Sovereign Prince" of the United Netherlands. He accepted this award on 21 July 1814.
On 16 November 1828, the envoys of the Great Powers (Britain, France and Russia) signed the first of a series of protocols concerning the boundaries of political identity of the new Greek state, to be established following the Greek War of Independence. The 1828 Protocol foresaw the establishment of an autonomous principality under Ottoman suzerainty, comprising only the Peloponnese peninsula and the southern Aegean islands.
On 22 March 1829, the 1828 Protocol was amended to more fully reflect the conclusions of the Poros Conference of the Powers' ambassadors to Greece and the Ottoman Empire. As a result, the extent of the Greek state was increased, with a new border line running from the Ambracian Gulf to the Pagasetic Gulf, including Negroponte (Euboea) and the Cyclades but not Crete. Greece was, however, to remain an autonomous tributary state under a prince that would explicitly not belong to the ruling families of the three powers. A further conference in London on 30 November of the same year decided that Greece should instead be given full independence, but its borders were moved back to the Aspropotamos River–Maliac Gulf line.
On 30 August 1832, a London Protocol was signed to ratify and reiterate the terms of the Treaty of Constantinople. The 1830 London Protocol affirmed the rights of Christians in the Ottoman Empire and the rights of Muslims in Greece
On 8 May 1852, after the First War of Schleswig, another London Protocol was signed. The international treaty that became known as the "London Protocol" was the revision of an earlier protocol, which had been ratified on 2 August 1850, by the major Germanic powers of Austria and Prussia. The second, actual London Protocol was recognised by the five major European powers, including Austria, France, Prussia, Russia, and the United Kingdom, as well as the Baltic Sea powers of Denmark and Sweden.
The Protocol affirmed the integrity of the Danish federation as a "European necessity and standing principle". Accordingly, the duchies of Schleswig (a Danish fief), and Holstein and Lauenburg (German fiefs) were joined by personal union with the Kingdom of Denmark. However, Frederick VII of Denmark was childless, so a change in dynasty was imminent and the lines of succession for the duchies and Denmark conflicted. That meant that, contrary to the Protocol, the new King of Denmark would not also be the new Duke of Holstein and Duke of Lauenburg. So for this purpose, the line of succession to the duchies was modified. Further, it was affirmed that the duchies were to remain as independent entities, and that Schleswig would have no greater constitutional affinity to Denmark than Holstein.
The major powers primarily wanted to ensure, by guaranteeing Denmark's territorial integrity, that the strategically significant port of Kiel would not fall into Prussian hands. Eleven years later, this treaty became the trigger for the German–Danish war of 1864. Prussia and Austria declared Denmark in violation of the Protocol, by the November Constitution, which Christian IX of Denmark signed on 18 November 1863. After an initial period of joint Austro–Prussian administration, Kiel was ultimately delivered to Prussia in 1867.
The London Protocol was signed on 21 March 1877 between Russia and the United Kingdom. The Russians agreed not to establish any client states in case they attained victory in the looming Russo–Turkish War. In return, the British agreed to remain neutral in any conflict between the Ottoman Empire and Russia. The agreement was an effort to maintain a balance of power in the Balkans and to avoid intervention by the other Great Powers. Russian attempts to create a large Bulgaria in the Treaty of San Stefano led to the British withdrawal from the Protocol and threatened military intervention, quieted only by the Congress of Berlin.
International Maritime Organisation, Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972, also known as the London Convention/Protocol 
The London Protocol is also an alternative name for the London Agreement (2000) between certain contracting States to the European Patent Convention, aiming to reduce the number of translations required of granted European patents.
The London Protocol is the revised and updated version of the original ‘Protocol for the Investigation and Analysis of Clinical Incidents’ first published in 1999 (Vincent et al., BMJ 1998; Vincent et al., BMJ 2000; Vincent, NEJM 2003).
The protocol outlined a process of incident investigation and analysis for use by clinicians, risk and patient safety managers, researchers and others wishing to reflect and learn from clinical incidents. This approach has now been refined and developed in the light of experience and research into incident investigation both within and outside healthcare. It is designed to be a structured process of reflection on incidents providing a ‘window on the healthcare system’ (Vincent, QSHC 2004) which can be adapted for use in many contexts and used either quickly for education and training or in substantial investigations of serious incidents. The London protocol is free to download and available in a number of languages.
Source : Imperial College London - refer to Charles Vincent http://www1.imperial.ac.uk/medicine/about/institutes/patientsafetyservicequality/cpssq_publications/resources_tools/the_london_protocol/
- Encyclopedia of World History 2001
- London Protocol 1830
- Hjelholt, Holger (1971). Great Britain, the Danish–German conflict and the Danish succession 1850–1852: From the London Protocol to the Treaty of London (the 2nd of August 1850 and the 8th of May 1852). Copenhagen, Denmark: Munksgaard. p. 38.
- Holt 1917, pp. 75–76.
- A more detailed account is available at the German-language article.
- IMO website
- European Patent Office Website