The most common organism in spinal infection is from the bacteria Staphylococcus aureus which typically exists on human skin, followed by Escherichia coli. Most spine infections occur in the lumbar spine because of the blood supply to this region of the spine.
Feudalism, a system of political and military relationships, evolved in western Europe. The feudal system was a simple but effective means of medieval government in which the king rented land to barons, who provided him knights and taxes
Feudalism developed from the weakness of government in late Roman and early mediaeval Europe and the need of small landowners for protection against enemies, invaders and other, more powerful, landowners. This need invoked the aid of two institutions already recognized in law, the patrocinium ... and the precarium....