Not us

High status families in late Neolithic and Bronze Age Germany kept slaves from other tribes which were genetically unrelated to them... 

Also, analysis of strontium and oxygen deposits in bone revealed that the men remained in the community across multiple generations. The women, in contrast, were largely born outside the area – some coming from region more than 350 km away, on the other side of the Alps...

This custom of marrying women from "unrelated" clans was preserved in the Balkans until recently. Men from my paternal grandfather's village always used to marry women from villages "across the river" who were "not one of us"...

Interestingly, the article entitled "History of Diplomacy" from Encyclopedia Britannica says that:

"...the earliest diplomatic negotiations occurred during the time of the earliest tribal societies which had to negotiate marriage, trade and hunting rights."

Diplomats are sent to the foreigners as the first contact (before all other) to represent us, (stand for us,  before us). Interestingly Greek word for embassy is "πρεσβεία" pronounced "presvia" which in Serbian literally means "before all other"??? I talked about this in my post "Embassy"...

Serbian wedding customs have preserved the memory of the time when getting a woman to marry was dangerous business. Wedding parties going to get the bride from her house to groom's house are little clan armies, armed to the teeth and ready for battle. I talked about this in my post "Wedding party graveyards"...