Vassal state

A vassal state is any state that has a mutual obligation to a superior state or empire, in a status similar to that of a vassal in the feudal system in medieval Europe. The obligations often included military support in exchange for certain privileges. In some cases, the obligation included paying tribute, but a state which does so is better described as a tributary state. Today, more common terms are puppet state, protectorate, client state, associated state or satellite state.
Historical examples.
Ancient Egypt.
The reign of Thutmose III (1479BCE-1425BCE) laid the foundations for the systems that functioned during the Amarna period of Egypt. Vassal states in the Levant became fully integrated in Egypt’s economy with the construction of harbours – allowing for greater communication and collection of tax between Egypt and its vassal states during this period.
Much of what is known about Egypt’s vassal states from the reigns of Amenhotep III and Tutankhamun (1390BCE-1323BCE) stems from the Amarna letters – a collection of 350 cuneiform tablets. The different ways vassal rulers communicated with the Pharaoh via grovelling and obsequiousness is a key method of extrapolating relationships between Egypt and vassal states.
Egypt’s key vassal states were located on the northern frontier, and included states such as Nuhasse, Qatna and Ugarit. These were located on the fringes of the territory claimed by Egypt and were a potential threat from acting with the Hittites in Anatolia, or the Mitanni in Iraq and Syria . Due to these vassal states’ distance from the Nile, and their value as a buffer zone from rival kingdoms, these states appeared to have a more high-status relationship with the pharaoh and Egypt. These states could also solicit the Pharaoh for various requests. The fulfilment of these asks by Egypt may have served the purpose of ensuring the loyalty of these distant vassal states. However, these vassal states were claimed by the Hittite Empire following the death of Akhenaten (1353BCE-1336BCE) and were never reclaimed.
Under Ramesses II (1279BCE-1213BCE), Egypt engaged in several military campaigns against the Hittites, eventually capturing the kingdoms of Kadesh and Amurru by taking advantage of growing problems in the Hittite Empire. In 1258BCE, Ramesses and the Hittite King Hattusili III signed a peace treaty that created a border from north of Biblos to Damascus between the two empires.
Biblos.
Correspondence with the kingdom of Biblos is well documented, as the longest interaction between Egypt and a vassal state and spanned a period of 12 years . The subject king in these letters – Rib-Hadda – is unique among vassal rulers as his letters are more verbose than other small rulers in the Near East. Despite his loyalty to the Pharaoh, Rib-Hadda never received any meaningful reply from Egypt during times of need and was eventually exiled from his own kingdom by his brother.
Hittite Empire.
The Hittite Empire incorporated vassal states that extended over much of Anatolia and Northern Syria. The addition of vassal states reached its peak under the reigns of Suppiluliuma I and Mursili II in the 14th Century BCE. The relationships between the Hittites and their vassal states centered around the Hittite king and the vassal ruler; the terms of their relationship were imposed unilaterally by the former, and accepted by the latter. Whenever a new Hittite king or vassal ruler came into power, a new treaty would be drawn up.
In rare cases, local rulers were given "kiurwana" (protectorate status). While they had distinct privileges such as exemption from tribute they did not have any more freedom of activity than other vassal states. All relations among the regions under Hittite control were strictly determined by the king. While this led to the belief that contact between vassal states was limited, it has also been thought that such restrictions were limited to the enemies of the Hatti.
The treaties imposed on vassal states came with military obligations, though vassals were also promised military assistance in return. Some treaties also contained details of annual tribute. Treaties were often concluded with a marriage between a vassal ruler and a Hatti princess of the royal family. The princess would hold greater power than other wives of the vassal, and succession would pass down her descendants.
Vassal states were obliged to support and swear fealty to the king’s legitimate successors as well. In the event of a usurper taking the throne, the vassal state was freed from all treaty obligations except to help restore a legitimate king to the throne. In doing so, vassal rulers were guaranteed sovereignty from themselves and their successors in their region.
Ugarit.
The relations of Ugarit are the most well-known of the Hittite’s vassal states. Sources on Ugarit’s role and relationship with the Hittites mostly comes from the Ugarit Archives, with only a few from Hittite sources. From the sources, it is believed that Ugarit held economic and commercial importance to the Hittite Empire, as many letters and documents relate to trade. Ugarit also maintained a relationship with Egypt, due to contacts with the pharaohs court. Most evidence of this contact comes from the era of the Pax Hethitica, which came after peace between Egypt and the Hittite Empire.
Neo-Assyrian Empire.
The vassal states of the Neo-Assyrian Empire (911BCE-609BCE) had a unique relationship with the Empire they became a part of. While vassal states were necessary to the politics of the empire and connected by administrative and economic means, they are not considered to be ‘properly Assyrian’. Neo-Assyrian imperial ideology placed importance on unified diversity, and as such vassal states maintained a degree of cultural independence. While territorial expansion slowed in the 7th century BCE, the amount of vassal states increased in number, suggesting a change in foreign policy.
Achaemenid Persia.
While the Persians made use of Satraps (appointed Persian governors) (Lendering 1996) rather than vassal rulers in subject regions, there were rare cases of vassal states being utilized. Herodotus writes that negotiations took place between king Amyntas I of Macedonia and the Persians after the former’s subjugation by the Achaemenids by 513BCE. The Macedonians became further connected to the Persians as Amyntas married his daughter to a Persian nobleman (Hdt. 5.21.). Under Darius I, Macedonia was organized into a regular tax district of the Empire (Hdt. 6.44.). Their control over Macedonia is attested in the DNa inscription at Naqsh-I-Rustam.
Amyntas’ son Alexander I supported Xerxes I during the Persian invasion of Greece. In 479BCE, the Achaemenid forces were defeated by the Greeks, and Macedonia was no longer considered Greek by other city-states.
Ancient China.
From the time of the Zhou Dynasty (1046–770 BC) until the Han Dynasty (206 BC–220 AD), a varying number of vassal states existed in ancient China.
These ranged in size from small city states to vassals which controlled large swathes of territory such as the States of Chu and Qi. One of these vassal states would go on to conquer China and unite the country under the first emperor Qin Shi Huang.
Ottoman Empire.
The Ottoman Empire (1299–1923) controlled a number of tributary or vassal states in the peripheral areas of its territory. Vassalage took a number of different forms with some states permitted to elect their own leaders. Other states paid tribute for their lands.
During the 18th century, the Ottoman Empire controlled many vassal and tributary states such as the principalities of Wallachia and Moldavia, or the Crimean Khanate.