Conscription
History: 

In pre-modern times: 

Ilkum: Around the reign of Hammurabi (1791–1750 BC), the Babylonian Empire used a system of conscription called Ilkum. Under that system those eligible were required to serve in the royal army in time of war. During times of peace they were instead required to provide labour for other activities of the state. In return for this service, people subject to it gained the right to hold land. It is possible that this right was not to hold land per se but specific land supplied by the state.
Various forms of avoiding military service are recorded. While it was outlawed by the Code of Hammurabi, the hiring of substitutes appears to have been practiced both before and after the creation of the code. Later records show that Ilkum commitments could become regularly traded. In other places, people simply left their towns to avoid their Ilkum service. Another option was to sell Ilkum lands and the commitments along with them. With the exception of a few exempted classes, this was forbidden by the Code of Hammurabi.

Medieval period: 

Medieval levies: Under the feudal laws on the European continent, landowners in the medieval period enforced a system whereby all peasants, freemen commoners and noblemen aged 15 to 60 living in the countryside or in urban centers, were summoned for military duty when required by either the king or the local lord, bringing along the weapons and armor according to their wealth. These levies fought as footmen, sergeants, and men at arms under local superiors appointed by the king or the local lord such as the arrière-ban in France. Arrière-ban denoted a general levy, where all able-bodied males age 15 to 60 living in the Kingdom of France were summoned to go to war by the King (or the constable and the marshals). Men were summoned by the bailiff (or the sénéchal in the south). Bailiffs were military and political administrators installed by the King to steward and govern a specific area of a province following the king's commands and orders. The men summoned in this way were then summoned by the lieutenant who was the King's representative and military governor over an entire province comprising many bailiwicks, seneschalties and castellanies. All men from the richest noble to the poorest commoner were summoned under the arrière-ban and they were supposed to present themselves to the King or his officials.
In medieval Scandinavia the leiðangr (Old Norse), leidang (Norwegian), leding, (Danish), ledung (Swedish), lichting (Dutch), expeditio (Latin) or sometimes leþing (Old English), was a levy of free farmers conscripted into coastal fleets for seasonal excursions and in defence of the realm.
The bulk of the Anglo-Saxon English army, called the fyrd, was composed of part-time English soldiers drawn from the freemen of each county. In the 690s laws of Ine of Wessex, three levels of fines are imposed on different social classes for neglecting military service.
Some modern writers claim military service in Europe was restricted to the landowning minor nobility. These thegns were the land-holding aristocracy of the time and were required to serve with their own armour and weapons for a certain number of days each year. The historian David Sturdy has cautioned about regarding the fyrd as a precursor to a modern national army composed of all ranks of society, describing it as a "ridiculous fantasy":

The persistent old belief that peasants and small farmers gathered to form a national army or fyrd is a strange delusion dreamt up by antiquarians in the late eighteenth or early nineteenth centuries to justify universal military conscription.

In feudal Japan the shogun decree of 1393 exempted money lenders from religious or military levies, in return for a yearly tax. The Ōnin War weakened the shogun and levies were imposed again on money lenders. This overlordism was arbitrary and unpredictable for commoners. While the money lenders were not poor, several overlords tapped them for income. Levies became necessary for the survival of the overlord, allowing the lord to impose taxes at will. These levies included tansen tax on agricultural land for ceremonial expenses. Yakubu takumai tax was raised on all land to rebuild the Ise Grand Shrine, and munabechisen tax was imposed on all houses. At the time, land in Kyoto was acquired by commoners through usury and in 1422 the shogun threatened to repossess the land of those commoners who failed to pay their levies.

Military slavery: The system of military slaves was widely used in the Middle East, beginning with the creation of the corps of Turkic slave-soldiers (ghulams or mamluks) by the Abbasid caliph al-Mu'tasim in the 820s and 830s. The Turkic troops soon came to dominate the government, establishing a pattern throughout the Islamic world of a ruling military class, often separated by ethnicity, culture and even religion by the mass of the population, a paradigm that found its apogee in the Mamluks of Egypt and the Janissary corps of the Ottoman Empire, institutions that survived until the early 19th century.
In the middle of the 14th century, Ottoman Sultan Murad I developed personal troops to be loyal to him, with a slave army called the Kapıkulu. The new force was built by taking Christian children from newly conquered lands, especially from the far areas of his empire, in a system known as the devşirme (translated "gathering" or "converting"). The captive children were forced to convert to Islam. The Sultans had the young boys trained over several years. Those who showed special promise in fighting skills were trained in advanced warrior skills, put into the sultan's personal service, and turned into the Janissaries, the elite branch of the Kapıkulu. A number of distinguished military commanders of the Ottomans, and most of the imperial administrators and upper-level officials of the Empire, such as Pargalı İbrahim Pasha and Sokollu Mehmet Paşa, were recruited in this way. By 1609, the Sultan's Kapıkulu forces increased to about 100,000.
In later years, Sultans turned to the Barbary Pirates to supply their Jannissaries corps. Their attacks on ships off the coast of Africa or in the Mediterranean, and subsequent capture of able-bodied men for ransom or sale provided some captives for the Sultan's system. Starting in the 17th century, Christian families living under the Ottoman rule began to submit their sons into the Kapikulu system willingly, as they saw this as a potentially invaluable career opportunity for their children. Eventually the Sultan turned to foreign volunteers from the warrior clans of Circassians in southern Russia to fill his Janissary armies. As a whole the system began to break down, the loyalty of the Jannissaries became increasingly suspect. Mahmud II forcibly disbanded the Janissary corps in 1826.
Similar to the Janissaries in origin and means of development were the Mamluks of Egypt in the Middle Ages. The Mamluks were usually captive non-Muslim Iranian and Turkic children who had been kidnapped or bought as slaves from the Barbary coasts. The Egyptians assimilated and trained the boys and young men to become Islamic soldiers who served the Muslim caliphs and the Ayyubid sultans during the Middle Ages. The first mamluks served the Abbasid caliphs in 9th-century Baghdad. Over time they became a powerful military caste. On more than one occasion, they seized power, for example, ruling Egypt from 1250 to 1517.
From 1250 Egypt had been ruled by the Bahri dynasty of Kipchak origin. Slaves from the Caucasus served in the army and formed an elite corps of troops. They eventually revolted in Egypt to form the Burgi dynasty. The Mamluks' excellent fighting abilities, massed Islamic armies, and overwhelming numbers succeeded in overcoming the Christian Crusader fortresses in the Holy Land. The Mamluks were the most successful defence against the Mongol Ilkhanate of Persia and Iraq from entering Egypt.
On the western coast of Africa, Berber Muslims captured non-Muslims to put to work as laborers. They generally converted the younger people to Islam and many became quite assimilated. In Morocco, the Berber looked south rather than north. The Moroccan Sultan Moulay Ismail, called "the Bloodthirsty" (1672–1727), employed a corps of 150,000 black slaves, called his Black Guard. He used them to coerce the country into submission.

In modern times: Modern conscription, the massed military enlistment of national citizens (levée en masse), was devised during the French Revolution, to enable the Republic to defend itself from the attacks of European monarchies. Deputy Jean-Baptiste Jourdan gave its name to the 5 September 1798 Act, whose first article stated: "Any Frenchman is a soldier and owes himself to the defense of the nation." It enabled the creation of the Grande Armée, what Napoleon Bonaparte called "the nation in arms", which overwhelmed European professional armies that often numbered only into the low tens of thousands.