236 EARLY MEDIEVAL SPAINthe shelter of the Asturian and Cantabrian mountains into the rela-
tive openness of the Meseta is symptomatic both of the sense of the
solidity of the new settlements and of the self-confidence of their
rulers.
Even when compared with their Asturian predecessors the kings of
Leon in the tenth century seem obscure. The quantity of charters
surviving from the Leonese kingdom greatly exceeds that produced
previously in the Asturias but this type of evidence is very limited in
its application, and the Leonese and Asturian charters are less varied
and more restricted in their style and contents than those of the
contemporary counties of Catalonia. However, it is in historical writ-
ing that this kingdom is deficient. For most of the tenth century,
from the last stages of the reign of Alfonso III to that of Ramiro III
(966-985) the chronological outline has to be taken from the Chronicle
of Sampiro, written by a court notary early in the succeeding century,
who may have become Bishop of Astorga (c. 1040). This survives in
two versions: one, probably faithful to the original, transmitted in the
twelfth century through the anonymous Leonese chronicle known,
misleadingly, as the Historia Silense, and the other, heavily interpo-
lated and expanded and with a continuation compiled (c. 1119) by
Bishop Pelagius of Oviedo, a notorious forger of texts. This latter
becomes the only source for the last two decades of the tenth century
and for the final stage of the Leonese kingdom, which went down in
military defeat at the hands of Fernando I, the Navarrese king of
Castille, in 1037. The only supplement to the Sampiro tradition, apart
from the brief references in Arab historians, comes from the continu-
ation of the Albelda chronicle up to 976 written by Abbot Vigila.
From these sources some account of the history of the kingdom
can be drawn. The events preceding the deposition of Alfonso III by
his sons in 910 are not clear, and it is possible that Sampiro was as
baffled by their chronology as we are. It seems that at the· end of a
period of some military successes against Umayyad expeditions, and
the expansion achieved by the repopulation of the Duero valley and
the frontier regions of Castille, Alfonso discovered a plot in which his
eldest son Garda was implicated, and he had him arrested at Zamora.
This action precipitated a revolt in Galicia led by its count, who was
Garda's father-in-law, and a further conspiracy by Alfonso's other
sons which resulted in the king's forcible deposition in 910. The
initial causes of discontent, other than the old monarch's inconvenient
longevity, are unknown, but one immediate consequence appears to