July 9 – Third Carlist War – Battle of Alpens: Campaigning in Catalonia, a government column under General José Cabrinety is ambushed at Alpens, 15 miles east of Berga, by Carlist forces under General Francisco Savalls. After heavy fighting, with Cabrinety killed, virtually the entire column of 800 men is killed or captured.
Third Carlist War – Battle of Mañeru: In continued campaigning in Navarre, Spanish Republican General Domingo Moriones meets a Carlist force under Nicolás Ollo at Mañeru, near Puente de la Reina, in a hard-fought but indecisive action. While both sides claim victory, the Carlists are said to have had the advantage, and a month later Moriones is repulsed in a costly assault further west, against Estella.
Third Carlist War – Battle of Montejurra: Determined to recapture the key city of Estella in Navarre, Spanish Republican General Domingo Moriones advances on the Carlists under General Joaquín Elío at nearby Montejurra. After very heavy fighting both sides claim victory, but Moriones withdraws, and Estella remains in Carlist hands. Don Carlos is present in the front line.
December 22 – Third Carlist War – Battle of Bocairente: Campaigning in Valenica, Spanish Republican General Valeriano Weyler is attacked at Bocairente, northwest of Alcoy, by a greatly superior Carlist force under General José Santés. Weyler is initially driven back, losing some of his guns, but in a brilliant counter-attack he turns defeat into victory, and Santés is heavily repulsed and forced to withdraw.
December 27 – Third Carlist War – Siege of Bilbao (until 2 May1874): Campaigning in Navarre, Pretender Don Carlos VII and General Joaquín Elío besiege Bilbao, held by General Ignacio del Castillo and 1,200 men. The Carlist force is ten times this number, and includes most of the troops from Navarre, Vizcaya and Álava, although a considerable force is left in Guipúzcoa. Despite defeat at nearby Somorrostro, Republican commander Marshal Francisco Serrano, supported by Generals Manuel de la Concha and Arsenio Martínez-Campos, brilliantly breaks the siege, and Concha then marches on Estella.