Aragonese-Castilian War (1109–1112)

Aragonese-Castilian War (1109–1112)

PRINCIPAL COMBATANTS: Aragon vs. Castile

PRINCIPAL THEATER(S): Castile, Spain

DECLARATION: None recorded

MAJOR ISSUES AND OBJECTIVES: A failed dynastic marriage
led the two expansive Christian powers into a
competitive war for dominance.

OUTCOME: Aragon succeeded in dominating Castile
briefly in an uneasy union and in expanding its influence
below the Ebro River.

APPROXIMATE MAXIMUM NUMBER OF MEN UNDER ARMS:
Unknown

CASUALTIES: Unknown

TREATIES: None

In the 12th century Christian Europe was engaged in the
slow reconquest of lands taken by the Muslims on the
Iberian Peninsula during the eighth century. Constant warfare
along a shifting Muslim-Christian frontier only
encouraged violent internal struggles on both sides of the
varying border, and as a result there sprang into existence a
number of all-but-independent principalities, kingdoms,
city-states, and emirates, which were only sporadically
subject to a central authority. Among those were Castile
and Aragon, the former about to launch on a half-century
of glorious expansion, the latter, smaller and obstinate,
beginning to wend its way slowly toward becoming the
dominant Mediterranean power in the century to follow.
Meanwhile, they vied for position, and in 1109 a dynastic
marriage was arranged between King Alfonso I “the Battler”
(1073[?]–1134) of Aragon and Queen Urraca (1081–
1126) of Castile. When the two monarchs fell to disputation,
however, the prospective union of Aragon and Castile
melted away. War erupted, and although Alfonso was victorious
in the Battle of Sepulveda in 1111, fighting continued
in a series of lesser clashes. The marriage between
Alfonso and Urraca was dissolved in 1112, as was the tenuous
union between their kingdoms. Alfonso returned to
Aragon, which he vigorously expanded, capturing Saragossa
from the Moors in 1118. This established Aragonese
influence below the Ebro River and elevated the kingdom
to dominance in the region.

Further reading: Raymond Carr, Spain: A History
(New York: Oxford University Press, 2000); Bernard F.
Reilly, The Medieval Spains (New York: Cambridge University
Press, 1993).