British foreign policy in the Middle East has involved multiple considerations, particularly over the last two and a half centuries. These included maintaining access to British India, blocking Russian or French threats to that access, protecting the Suez Canal, supporting the declining Ottoman Empire against Russian threats, guaranteeing an oil supply after 1900 from Middle East fields, protecting Egypt and other possessions in the Middle East, and enforcing Britain's naval role in the Mediterranean. The timeframe of major concern stretches from the 1770s when the Russian Empire began to dominate the Black Sea, down to the Suez Crisis of the mid-20th century and involvement in the Iraq War in the early 21st. These policies are an integral part of the history of the foreign relations of the United Kingdom.