First Era: Unknown - 535 A.D.

The population is primarily composed of tribal groups, located in Northwestern Europe. Agriculture, nomadic, and hunter/forager lifestyles are practiced by different tribes, with some tribes practicing a mixture of lifestyles. Tribes often carry out raids on human groups and other tribes, taking young and juvenile captives and incorporating them into their tribe. Belief systems are mostly shamanistic in nature, and consist of a mixture of polytheistic, monotheistic, and animistic religions. A marked belief of iron as an evil substance exists through several tribes, believed to result from the observation of tetanus infectees. Mutual superstition and suspicion exist between humans and SCP-2615-A. Towards the end of the period, SCP-2615-A tribes begin to unite into larger groups.

Middle Era: 535 A.D. - 1772 A.D.

For approximately a century, the large groups created by the combination of tribes wage constant war against other groups for land, resources, and political power. Near the end of this century, SCP-2615-B stabilizes into 27 distinct nations, the largest and most powerful of which is based in the British Isles and some areas of France, Belgium, the Netherlands, Norway, Germany, and Denmark. In this and 18 of the other nations, SCP-2615-B is composed of self-regulating and self-sustaining groups of extended family, with some intermarriage between family groups, which pay allegiance and tribute to a central monarch.

In 7 of the remaining nations, governing bodies are composed of representative democracies and land is divided into smaller city-states, each regulated by a smaller democratic system composed of the patriarchs and matriarchs of family groups. Each state democracy then would send a representative to the national government. The final nation consisted of a two-party political system, with the two parties referred to as the "Summer Court" and "Winter Court". Each SCP-2615-A instance would decide their party at the age of 15, at which point they were considered an adult. Members of each party were expected to regulate and control other members of their own party. Intermarriage between members of the two parties was forbidden. From late spring to early fall, members of the Summer Court had full control over members of the Winter Court. From late fall to early spring, members of the Winter Court had full control over members of the Summer Court. SCP-2615-A most commonly set up their territories and dwellings in rural areas and areas unpopulated by humans.

Though small territorial disputes occurred over the next millennia, most wars were short, caused little damage, and did not cause any large-scale power shifts. From the fifteenth to seventeenth centuries, SCP-2615-B nations began to create colonies across Europe, Africa, Asia, and the Americas.

During this time period, there is a marked increase in the presence of anomalies in SCP-2615-B. In most cases, low-level anomalies are utilized by SCP-2615-A for entertainment and utility. In other cases, high-level anomalies form the basis for religions.

During this period, there is a slight increase in human/SCP-2615 interactions. Though still rare, SCP-2615 instances will occasionally enter business agreements with humans for an exchange of goods or services. SCP-2615-A also widely begin the practices of abducting human infants and raising them in SCP-2615-B and of planting SCP-2615-A instances to be raised in human society.

Modern Era: 1772 A.D. - Present Day

SCP-2615 have spread across the globe, mostly populating areas with low or no human population. Some major human and SCP-2615 cities act as hubs for SCP-2615/human coexistence. Some SCP-2615 instances are also known to utilize extradimensional spaces for the formation or expansion of nations and to prevent overpopulation.

Most SCP-2615 territories swear allegiance to one of 25 of the original 27 SCP-2615-B nations, with two of the original monarchies being incorporated into the largest monarchy. The existence of these territories has changed the geopolitical status of several baseline nations, with most nations having a lesser amount of territory, and many nations having an increase or decrease of wealth or power based on proximity to and relations with SCP-2615 nations.

Notable widespread integration of anomalies into SCP-2615-B and the daily lives of SCP-2615-A. Some overflow of anomalies into human life and society. The Foundation and most groups of interest still in operation, but with no interest in maintaining the secrecy of the anomalous and having a more relaxed attitude towards anomalies.