Southern Asia 1927: Treaty of Jeddah
In December 1925 the Saudis completed their conquest of Hejaz, creating the Kingdom of Hejaz and Nejd. In order to gain British recognition of his conquests, Ibn Saud signed the Treaty of Jeddah, agreeing not to threaten the numerous British protectorates which surrounded his new kingdom.
Changes to the map 24 August 1925–20 May 1927
Unification of Saudi Arabia: The Saudis have completed their conquest of Hejaz, capturing Jeddah and Medina in late 1925. In the Hadda Agreement, they have defined their boundary with Transjordan. At the Treaty of Jeddah, Britain has recognized the Saudi conquests and the new Kingdom of Hejaz and Nejd.
Yemen and Asir: Yemen has attacked Lower Audhali but has been repulsed by the British. Fear of Yemen has led Asir to seek Saudi protection.
Mosul Question: The League of Nations has recommended Iraq retain Mosul, leading Turkey to cede its claim to the region.
Northern Expedition: Chiang Kaishek and the Chinese Nationalists (Kuomintang) have launched their invasion of central China. However Chiang's purge of the Chinese Communists has prompted a rival pro-Communist Kuomintang government to set itself up in Wuhan.
Somalia: Italy has annexed Trans-Juba to Italian Somaliland.
British Protectorates in the Persian Gulf
The British Residency of the Persian Gulf maintains British India influence in a number of Gulf states. These states are nominally independent - and shown as such in most atlases from the period - but have all signed treaties guaranteeing British control over their foreign affairs.
The Sultanate of Muscat and Oman is the only one of these states with significant international relations, having obtained trade agreements with the US and France before it signed its treaty with Britain. Maps of the time often show Trucial Oman and even Qatar as regions of Oman.
Trucial Oman is the region to the west of Oman which collectively signed treaties with Britain. The sheikhdoms of this region are often called the Trucial States, and will become the United Arab Emirates. However at this time they have little unity, with no regional council until 1952.
The British Indian Empire, also known as the British Raj, is comprised of a complex of presidencies, provinces, protectorates, and agencies. Only the top level subdivisions are shown here.
The area under direct British rule is known as British India and made up of presidencies and provinces - a presidency simply being the name for an older province.
Outside British India, but often included within the sphere of the presidencies/provinces, are the hundreds of protectorates or 'princely states'. These are indirectly ruled states, the largest being Hyderabad, Kashmir, and Mysore. The others are either collected into agencies - which may in turn contain other smaller agencies - or fall under the sway of the provinces.
2 Nov 1925 Hadda Agreement▲
The British-mandated Emirate of Transjordan signed the Hadda Agreement with the Sultanate of Nejd, formally defining the boundary between the two countries in the wake of the Kuwait Conference. The agreement concluded by stating that it would "remain in force for so long as His Britannic Majesty's Government [was] entrusted with the Mandate for Trans-Jordan"
12 Dec 1925 Pahlavi Dynasty▲
The Majlis of Persia declares Reza Khan, the former Prime Minister, as the Shah of Persia, having deposed and formally exiled Ahmad Shah Qajar in October. Three days later, on 15 December, Reza Khan takes the imperial oath, becoming Reza Shah Pahlavi - the first shah of the Pahlavi dynasty.
16 Dec 1925 Mosul Award▲
After sending a fact-finding commission to the region, the League of Nations concludes that the Mosul Vilayet - disputed between the Turkish Republic and British controlled Kingdom of Iraq - belongs to Iraq. Turkey protests the decision but agrees to cede its claim in June 1926 in return for a share of oil profits.
17–19 Dec 1925 Fall of Jeddah and Medina▲
Under siege since February 1925 and with their supplies running out, the chiefs of Jeddah agree to surrender their city to the Saudi forces of the Sultanate of Nejd, while King Ali bin Hussein of Hejaz flees to Baghdad via the Red Sea. Medina falls to the Saudis two days later, effectively completing the Saudi conquest of the Kingdom of Hejaz.
1 Jul 1926 Northern Expedition▲
Generalissimo Chiang Kaishek, leader of the Kuomintang (KMT), declares the start of the Northern Expedition, intending to end warlord rule in northern China and reunify China under the KMT. With 100,000 soldiers of the National Revolutionary Army, Chiang invades northern Hunan from the south, capturing Changsha on 11 July.
20 May 1927 Treaty of Jeddah▲
Sir Gilbert Clayton, the British emissary and former head of the Arab Bureau, signs the Treaty of Jeddah with Ibn Saud, King of the Kingdom of Nejd and Hejaz, at Jeddah, Hejaz. The treaty formally recognizes Ibn Saud's independence and sovereignty over the new frontiers of the Kingdom of the Nejd and Hijaz in return for Ibn Saud's agreement to stop his forces from harassing the neighboring British protectorates.