Bosrei
The Bosrei were a group of ancient proto-Germanic tribes that inhabited southern Eracura in the Bosrei Peninsula and the surrounding regions, north of present day Syara and Ruvelka. The Bosrei appeared in the peninsula sometime around the 8th century BCE, either displacing pre-existing tribes or incorporating them into their culture. Little is known of their early history due to an absence of written records, other than the Bosrei were divided into numerous competing clans and petty kingdoms. Between 500 BCE to 200 CE many Bosrei tribes turned to the Sundering Sea for expansion, raiding and plundering the coast of northern Siduri, leading to brief conflicts with the Ruvelkan Kingdoms and the Makedonian Empire.
Beginning around the 3rd to 2nd century BCE Makedonian and Syaran settles began colonizing the coast of the Bosrei Peninsula, on more than one occasion leading to conflict with some Bosrei kingdoms and tribes. Tensions overall remained low between the two groups up until the mid-Second Century CE when the Bosrei began rallying behind the warlord turned self-proclaimed King Angultha. Angultha would conquer and destroy several Syaran holdings in southern Eracura, reducing Syaran presence to a handful of holdouts. Seeing an opportunity to re-assert Makedonian influence and expand the borders of the Empire, King Anaximenes launched an expiditionary campaign against the Bosrei in 351 CE. Over the course of 15 years the Makedonians steadily reduced and eventually conquered most of the Bosrei tribes, bringing the peninsula under their control.
Following their subjugation by the Makedonians many Bosrei became slaves or levy soldiers of the Makedonian armies in their campaigns throughout the rest of Siduri. The interaction with the Bosrei marked the extent of Makedonian expansion into Eracura, which would last for roughly 500 years before Makedonian influence would began to wane, eventually coalescing into nothing more than coastal settlements by the 10th century. For reasons that are still not entirely certain, the Bosrei did not re-emerge in the wake of Makedon's recession to a significant degree, and they had largely faded from history by the 12th century, either abosrbed by neighboring nations or having migrated elsewhere.
Little is known of Bosrei culture and language, as they did not keep extensive written records of their own. Most knowledge of the Bosrei come from Makedonian sources, which are typically biased and incomplete. The Bosrei, like the Bastarnae, remain largely a mystery to modern researcher and many myths and speculative theories have arisen to explain their origin, culture, and fate.