A protectorate, in its inception adopted by modern international law, is a dependent territory that has been granted local autonomy and some independence while still retaining the suzerainty of a greater sovereign state. In exchange for this, the protectorate usually accepts specified obligations, which may vary greatly, depending on the real nature of their relationship. Therefore, a protectorate remains an autonomous part of a sovereign state. They are different from colonies as they have local rulers and people ruling over the territory and experience rare cases of immigration of settlers from the country it has suzerainty of. However, a state which remains under the protection of another state but still retains independence is known as a protected state and is different from protectorates.
In amical protection, the terms are often very favorable for the protectorate. The political interest of the protector is frequently moral (a matter of accepted moral obligation, prestige, ideology, internal popularity, dynastic, historical, or ethno-cultural ties) or countering a rival or enemy power (e.g., preventing the rival from obtaining or maintaining control of areas of strategic importance). This may involve a very weak protectorate surrendering control of its external relations; this, however, may not constitute any real sacrifice, as the protectorate may not have been able to have similar use of them without the protector's strength.
Amical protection was frequently extended by the great powers to other Christian (generally European) states and to smaller states that had no significant importance. In the post-1815 period, non-Christian states (such as China's Qing dynasty) also provided amical protection towards other much weaker states.
In modern times, a form of amical protection can be seen as an important or defining feature of microstates. According to the definition proposed by Dumienski (2014): "microstates are modern protected states, i.e. sovereign states that have been able to unilaterally depute certain attributes of sovereignty to larger powers in exchange for benign protection of their political and economic viability against their geographic or demographic constraints". Examples of microstates understood as modern protected states include Liechtenstein, San Marino, Monaco, Niue, the Cook Islands, and Palau.