In the campaign participated John of Castile, Juan Manuel of Villena, Diego López V de Haro, Juan Núñez II de Lara, Alonso Pérez de Guzmán, Fernán Ruiz de Saldaña, and other Castilian magnates and ricoshombres.
Also took part in the enterprise the council militias of Salamanca, Segovia, Seville and other cities.
For its part, King Denis of Portugal, father-in-law of Ferdinand IV, sent a contingent of 700 knights under the command of Martín Gil de Sousa, and James II of Aragon contributed to the expedition against Algeciras with 10 galleys.
Pope Clement V, by the bull "Prioribus, decanis" issued on 29 April 1309 in the city of Avignon, granted Ferdinand IV a tenth of all the ecclesiastical revenues of his Kingdoms for three years, in order to contribute to the maintenance of the war against the Kingdom of Granada.

From the city of Toledo, Ferdinand IV went to Córdoba, where the emissaries of James II of Aragon announced that he was ready to begin the siege of Almería.
In the city of Córdoba Ferdinand IV again discussed the campaign plan, because his brother the Infante Peter of Castile, John of Castile, Juan Manuel of Villena and Diego López V de Haro, among others, were opposed to the project of besiege the city of Algeciras, since all of them preferred to plunder and devastate the Vega de Granada through a series of successive attacks that would demoralize the Granada Muslims.
Nevertheless, the will of Ferdinand IV prevailed and the Castilian-Leonese troops prepared to besiege Algeciras.
The last preparations of the campaign were made in the city of Seville, to which Ferdinand IV arrived in early July 1309.
The provisions and supplies accumulated in the city of Seville by the Castilian-Leonese army were transferred by the Guadalquivir river, and then by sea to Algeciras.

On 27 July 1309, a part of the Castilian-Leonese army was found before the walls of the city of Algeciras, and three days later, on 30 July, arrived Ferdinand IV and John of Castile accompanied by numerous ricoshombres.
James II of Aragon began to besiege the city of Almería on 15 August, and the siege lasted until 26 January 1310.
A few days after the start of the siege of Algeciras, Ferdinand IV sent Juan Núñez II de Lara, Alonso Pérez de Guzmán, the Archbishop of Seville, the council of the city of Seville and the Master of the Order of Calatrava to besiege Gibraltar, who capitulated before the Castilian troops on 12 September 1309 after a brief and hard siege.

In mid-October 1309, John of Castile, his son Alfonso de Valencia, Juan Manuel of Villena and Fernán Ruiz de Saldaña, deserted and left the Christian camp located before Algeciras, being accompanied in their flight by others 500 knights.
This action, motivated by the fact that Ferdinand IV owed them certain sums of money for the payment of their soldiers, provoked the indignation of the European courts and the protest of James II of Aragon, who tried to persuade the deserters, though unsuccessfully, to return to the siege of Algeciras.
However, Ferdinand IV, who had the support of his brother, the Infante Peter, Juan Núñez II de Lara and Diego López V de Haro, persisted in his attempt to conquer Algeciras.

The scarcity and poverty of means in the Christian camp became so alarming that Ferdinand IV was obliged to pawn the jewels and crowns of his wife Queen Constance in order to be able to pay the soldiers and the crews of the galleys.
Shortly afterwards arrived at the Christian camp the troops of the Infante Philip of Castile and the Archbishop of Santiago de Compostela, who came accompanied by 400 knights and a good number of peons.
At the end of 1309, Diego López V de Haro became seriously ill as a result of a gout attack, which added to the death of Alonso Pérez de Guzmán, the rainy season that flooded the Christian camp, and the desertion of the John of Castile and Juan Manuel of Villena.
Nevertheless, in spite of these adversities, Ferdinand IV persisted until the last moment in his objective to capture Algeciras, although in the end he abandoned this purpose.

In January 1310 Ferdinand IV
In the campaign participated John of Castile, Juan Manuel of Villena, Diego López V de Haro, Juan Núñez II de Lara, Alonso Pérez de Guzmán, Fernán Ruiz de Saldaña, and other Castilian magnates and ricoshombres. Also took part in the enterprise the council militias of Salamanca, Segovia, Seville and other cities. For its part, King Denis of Portugal, father-in-law of Ferdinand IV, sent a contingent of 700 knights under the command of Martín Gil de Sousa, and James II of Aragon contributed to the expedition against Algeciras with 10 galleys. Pope Clement V, by the bull "Prioribus, decanis" issued on 29 April 1309 in the city of Avignon, granted Ferdinand IV a tenth of all the ecclesiastical revenues of his Kingdoms for three years, in order to contribute to the maintenance of the war against the Kingdom of Granada.
From the city of Toledo, Ferdinand IV went to Córdoba, where the emissaries of James II of Aragon announced that he was ready to begin the siege of Almería. In the city of Córdoba Ferdinand IV again discussed the campaign plan, because his brother the Infante Peter of Castile, John of Castile, Juan Manuel of Villena and Diego López V de Haro, among others, were opposed to the project of besiege the city of Algeciras, since all of them preferred to plunder and devastate the Vega de Granada through a series of successive attacks that would demoralize the Granada Muslims. Nevertheless, the will of Ferdinand IV prevailed and the Castilian-Leonese troops prepared to besiege Algeciras. The last preparations of the campaign were made in the city of Seville, to which Ferdinand IV arrived in early July 1309. The provisions and supplies accumulated in the city of Seville by the Castilian-Leonese army were transferred by the Guadalquivir river, and then by sea to Algeciras.
On 27 July 1309, a part of the Castilian-Leonese army was found before the walls of the city of Algeciras, and three days later, on 30 July, arrived Ferdinand IV and John of Castile accompanied by numerous ricoshombres. James II of Aragon began to besiege the city of Almería on 15 August, and the siege lasted until 26 January 1310. A few days after the start of the siege of Algeciras, Ferdinand IV sent Juan Núñez II de Lara, Alonso Pérez de Guzmán, the Archbishop of Seville, the council of the city of Seville and the Master of the Order of Calatrava to besiege Gibraltar, who capitulated before the Castilian troops on 12 September 1309 after a brief and hard siege.
In mid-October 1309, John of Castile, his son Alfonso de Valencia, Juan Manuel of Villena and Fernán Ruiz de Saldaña, deserted and left the Christian camp located before Algeciras, being accompanied in their flight by others 500 knights. This action, motivated by the fact that Ferdinand IV owed them certain sums of money for the payment of their soldiers, provoked the indignation of the European courts and the protest of James II of Aragon, who tried to persuade the deserters, though unsuccessfully, to return to the siege of Algeciras. However, Ferdinand IV, who had the support of his brother, the Infante Peter, Juan Núñez II de Lara and Diego López V de Haro, persisted in his attempt to conquer Algeciras.
The scarcity and poverty of means in the Christian camp became so alarming that Ferdinand IV was obliged to pawn the jewels and crowns of his wife Queen Constance in order to be able to pay the soldiers and the crews of the galleys. Shortly afterwards arrived at the Christian camp the troops of the Infante Philip of Castile and the Archbishop of Santiago de Compostela, who came accompanied by 400 knights and a good number of peons. At the end of 1309, Diego López V de Haro became seriously ill as a result of a gout attack, which added to the death of Alonso Pérez de Guzmán, the rainy season that flooded the Christian camp, and the desertion of the John of Castile and Juan Manuel of Villena. Nevertheless, in spite of these adversities, Ferdinand IV persisted until the last moment in his objective to capture Algeciras, although in the end he abandoned this purpose.
In January 1310 Ferdinand IV
Ferdinand IV of Castile