The early Middle Ages was a period of great monastic expansion all over Iberia, but it was the patronage of a magnate family that set certain monasteries apart from smaller institutions. In Galicia, riches and political influence are most synonymous with the family that founded Celanova, as many of the charters of the Tumbo attest. Particularly revealing in this respect is a charter dating to the spring of 934, which describes how Rosendo and his siblings oversaw the division of the family inheritance, much of which would later enlarge the holdings of Celanova, founded just two years later. Even at this stage the family portfolio consisted of dozens of estates, stretching from the northernmost tip of Galicia to the Coimbra region of Portugal, creating a patrimony vast in size and geographical spread. Yet it was not just the scale of these holdings that Rosendo and his family were keen to emphasise: the charter's commissioners were at pains to reveal that some of this property had been acquired in the ninth century, and that longstanding family interest underpinned its procurement. The tenth century would see this story of relentless patrimonial growth continue thanks to formalised and targeted campaigns of acquisition by Celanova, and while the parameters of wider society would change in response to the monastery's increasingly assertive presence, the Tumbo also captures something of this society's attempts to right wrongs for the common good. It is the governing structures that made these attempts possible.

Governing, like business, was a family affair in early medieval Galicia. But while business was the calling of the world at large, governing was more properly the province of its richest families. Portela Silva and Pallares Méndez have whittled down the major families of the region to just four, all of them implicated in the government of the region to a greater or lesser degree, but there can be little doubt that the family recorded in the colmellum divisionis of 934 was the most powerful in ninth- and tenth-century Galicia. To understand something of how this came to be we must recognise that the sources of the family's power were not solely to be found in buying land and receiving it in gift: they were also located in an appetite for political manoeuvring abundantly evidenced in the surviving source material.