The Optimates gather their forces to oppose Caesar with astonishing speed.
Their army includes forty thousand men (about ten legions), a powerful cavalry force led by Caesar's former right hand man, the talented Titus Labienus, forces of allied local kings and sixty war elephants.
The two armies engage in small skirmishes to gauge the strength of the opposing force, during which two legions switch to Caesar's side.
Meanwhile, Caesar expects reinforcements from Sicily.
Thapsus, originally founded by Phoenicians near a salt lake on a point of land eighty stadia (14.8 km) from the island of Lampedusa, serves as a marketplace on the coast of the province Byzacena in Africa Propria.
In the beginning of February, Caesar arrives in Thapsus and besieges the city, blocking the southern entrance with three lines of fortifications.
The Optimates, led by Metellus Scipio, cannot risk the loss of this position and are forced to accept battle.
Caesar's archers attacks the elephants, causing them to panic and trample their own men.
The elephants on the left flank charge against Caesar's center, where Legio V Alaudae is placed.
This legion sustains the charge with such bravery that afterwards they will wear an elephant as a symbol.
After the loss of the elephants, Metellus Scipio starts to lose ground.
Caesar's cavalry outmaneuvers its enemy, destroys the fortified camp, and forces its enemy into retreat.
King Juba's allied troops abandon the site and the battle is decided.
Roughly ten thousand enemy soldiers want to surrender to Caesar, but are instead slaughtered by his army.
This action is unusual for Caesar, who is known as a merciful victor.
Some sources contend Caesar had an epileptic seizure during the battle and was not fully conscious for its aftermath.
Scipio himself escapes, only to commit suicide months later in a naval battle near Hippo.
Following the battle, Caesar renews the siege of Thapsus, which eventually falls.
Caesar exacts a payment of fifty thousand sesterces from the vanquished.
Their defeat marks the end of opposition to Caesar in Africa.
Thapsus now becomes a Roman colony.