Religious conversion in the context of "Roman Catholicism"

An ethnicity or ethnic group is a group of people who identify with each other on the basis of perceived shared attributes that distinguish them from other groups. Attributes that ethnicities believe to share include language, culture, common sets of ancestry, traditions, society, religion, history, or social treatment. Ethnicities are maintained through long-term endogamy and may have a narrow or broad spectrum of genetic ancestry, with some groups having mixed genetic ancestry. Ethnicity is sometimes used interchangeably with nation, particularly in cases of ethnic nationalism. It is also used interchangeably with race although not all ethnicities identify as racial groups.

By way of assimilation, acculturation, amalgamation, language shift, intermarriage, adoption and religious conversion, individuals or groups may over time shift from one ethnic group to another. Ethnic groups may be divided into subgroups or tribes, which over time may become separate ethnic groups themselves due to endogamy or physical isolation from the parent group. Conversely, formerly separate ethnicities can merge to form a panethnicity and may eventually merge into one single ethnicity. Whether through division or amalgamation, the formation of a separate ethnic identity is referred to as ethnogenesis.

Religious assimilation refers to the adoption of a majority or dominant culture's religious practices and beliefs by a minority or subordinate culture. It is an important form of cultural assimilation.

Religious assimilation includes the religious conversion of individuals from a minority faith to the dominant faith. It can also include the religious indoctrination of children into a dominant religion by their converted parents. However, religious assimilation need not involve wholesale adoption of a dominant religious belief system by a minority; the concept is broad enough to include alterations in the frequency of religious participation to match that of the dominant culture. Indeed, religious assimilation among immigrant groups most commonly involves such minor changes, rather than sweeping change in religious belief systems.

The Islamization of Egypt occurred after the seventh-century Muslim conquest, in which the Islamic Rashidun Caliphate seized control of Egypt from the Christian dominated Byzantine Empire. Egypt and other conquered territories in Africa gradually underwent a large-scale conversion from Christianity to Islam, motivated in part by a jizya tax for those who refused to convert. Islam became the faith of the majority of the population at some point between the 13th and 14th centuries, and Arabic became the main language, replacing Coptic and Greek, which had previously served as the vernacular and governmental languages, respectively.

The Christianization of Scandinavia, as well as other Nordic countries and the Baltic countries, took place between the 9th and the 12th centuries. The realms of Denmark, Norway and Sweden established their own archdioceses, responsible directly to the pope, in 1104, 1154 and 1164, respectively. The conversion to Christianity of the Scandinavian people required more time, since it took additional efforts to establish a network of churches.

The earliest signs of Christianization were in the 830s with Ansgar's construction of churches in Birka and Hedeby. The conversion of Scandinavian kings occurred over the period 960–1020. Subsequently, Scandinavian kings sought to establish churches, dioceses and Christian kingship, as well as destroy pagan temples. Denmark was the first Scandinavian country to Christianize, as Harald Bluetooth declared this around AD 965, and raised the larger of the two Jelling Stones. According to historian Anders Winroth, Christianity was not forced upon Scandinavians by foreign states or foreign missionaries, but instead willfully adopted by Scandinavian kings who saw the religion as politically advantageous.

Apostasy in Islam (Arabic: ردة, romanized: ridda or ارتداد, irtidād) is commonly defined as the abandonment of Islam by a Muslim, in thought, word, or through deed. It includes not only explicit renunciations of the Islamic faith by converting to another religion or abandoning religion altogether, but also blasphemy or heresy by those who consider themselves Muslims, through any action or utterance which implies unbelief, including those who deny a "fundamental tenet or creed" of Islam. An apostate from Islam is known as a murtadd (مرتدّ).

While Islamic jurisprudence calls for the death penalty of those who refuse to repent of apostasy from Islam, what statements or acts qualify as apostasy, and whether and how they should be punished, are disputed among Muslim scholars, with liberal Islamic movements rejecting physical punishment for apostasy. The penalty of killing of apostates is in conflict with international human rights norms which provide for the freedom of religions, as demonstrated in human rights instruments such as the Universal Declaration of Human Rights, the International Covenant on Civil and Political Rights, and the International Covenant on Economic, Social and Cultural Rights provide for the freedom of religion.Until the late 19th century, the majority of Sunni and Shia jurists held the view that for adult men, apostasy from Islam was a crime as well as a sin, punishable by the death penalty, but with a number of options for leniency (such as a waiting period to allow time for repentance or enforcement only in cases involving politics), depending on the era, the legal standards and the school of law. In the late 19th century, the use of legal criminal penalties for apostasy fell into disuse, although civil penalties were still applied.