Lit.: "encircling cavalry"
A type of samurai organization started in the Sengoku, the Umamawari was composed of the cavalry who escorted, attended upon, and protected the commander. They were used as messengers and decisive units in battles. In peacetime they attended upon their daimyo, acting as guards and carrying out whatever tasks were needed.
The Oumamawari-shuu of the Later Houjou Clan, also called the Odawara-shuu (as the Houjou Clan's samurai were organized and named by the castles at which they served) was quite famous during the Sengoku.