The battle was a disaster for the Christians and many of the high nobility of León, including seven counts, died in the fray or were beheaded afterwards, while the heir-apparent, Sancho Alfónsez, was murdered by villagers while trying to flee.

The Christian sources nearest in time are the Crónica Najerense, connected to Nájera, and the Historia Compostelana, written from the perspective of the church of Santiago de Compostela.

The Spanish historiography of the battle was dominated by Prudencio de Sandoval until 1949, when Ambrosio Huici Miranda began to edit and compile the Arabic sources (published 1955).

A contingent of townsmen from Calatañazor, Alcalá, and Toledo, led by their alcaldes, numbering probably 750, mostly infantry but some light cavalry, joined the main force before the battle.

Tamim assembled his force with the Córdobans under Muhammad ibn Abi Ranq in front, his own Granadans behind them; the Valencians and Murcians made up the flanks.

Though initially successful against the Córdobans, the charging Christians were quickly surrounded while engaging the Granadans and the main force retreated to their camp.

The only count to escape was Álvar Fáñez, who led a large body of horse north to organise the defence of the upper Tagus.