Battle of Vatalandi
The Battle of Vatalandi was a military engagement between the Almoravid troops and the Portuguese at Vatalandi, near Santarém. The Almoravids were victorious.

After the death of Alfonso VI of León and Castile, the Muslim inhabitants of Sintra, which was under Christian control, revolted in 1109. The Portuguese count, Henry quickly arrived and captured the castle, putting down the revolt. The next year, 1110, saw the Almoravid leader, Syr ibn Abi Bakr, subduing the Muslim west of Andalusia. The Almoravid forces had already crossed the Tagus River, making an entry to Extremadura. Henry, however, feared that the spirit of the rebellion would spread to other towns nearby, which they mutually assisted each other.Francisco de S. Luiz, p. 176Alexandre Herculano, p. 219

Seeing the Almoravid campaigning in Extremadura and fearing another rebellion, Count Henry sent troops to reinforce the garrison of Santarém in early 1110. An important place he wanted to protect. The Portuguese forces were under Soario Fromariges and Mido Crescones. The Portuguese marched carelessly, encamped at a place called Vatalandi, and erected their tents to rest. However, the Almoravids crossed the Tagus, alongside Andalusians and Arabs. Knowing the Portuguese were small in numbers, they attacked and routed them, inflicting heavy casualties. The wounded were massacred. The commanders, Soario and Mido were killed in the battle.Francisco de S. Luiz, p. 176Alexandre Herculano, p. 219Christóvam Ayres, p. 313

The location of Vatalandi remains unknown.Barrilaro Ruas, Henrique (1949). A data do desastre de Vatalandi, p. 372. According to José Mattoso, Vatalandi is near Santarém.José Mattoso (1989), O castelo e a Feira, a Terra de Santa Maria nos séculos XI a XIII, p. 136. Perhaps in Valada, in the municipality of Cartaxo.João Diogo Rodrigues de Carvalho (2022), Santarém e a Reconquista: a tomada da cidade em 1147, p. 34.
References

Category:12th century in Portugal
Category:Battles involving Portugal
Category:Battles of the Reconquista
Category:Battles involving the Almoravid dynasty
Category:Conflicts in 1110
Category:County of Portugal
Category:12th century in al-Andalus
Sources
Alexandre Herculano (1901), Historia de Portugal, Vol I.

Christóvam Ayres de Magalhães Sepúlveda (1902), História orgânica e política do exército portuguêz, Vol. III.

Francisco de S. Luiz (1873), Obras completas do cardeal Saraiva, Vol II.