
Rodrigo Díaz de Vivar was a Castilian leader in Spain, back the 11th century. He grew up at the King’s Ferdinand I court, and when the latter died, his kingdom was split up among his three sons: Sancho II, the eldest, received the Castile region, and when accessing the throne, he appointed Rodrigo commander of the army.
Later to be nicknamed “El Cid” or “El Campadeor”, Rodrigo was admired for his military tactics, which pioneered modern warfare strategy – he would for instance gather his army before battling and “coach” his men about the strategy to deploy, gathering suggestions, sketching out the armies’ moves. As the Spanish author José Luis Olaizola portrayed, El Cid used to “drawing maps on parchments showing in different colors the deployments and maneuvers of horse cavalry, camel corps, archers, and foot soldiers.”
The three brothers who had inherited part of their father’s kingdom, namely Sancho, Alfonso and García, began to covet one another’s territory, teaming up and then betraying each other: during this tactical war, Toro, the city ruled by their own sister Elvira, fell. Sancho was eventually assassinated in 1072, and his murderer managed to escape despite El Cid’s chase after him… Alfonso then accessed the throne, and imprisoned his younger brother to take control of the empire as a whole.

There was no doubt that Rodrigo was not to benefit from that shift of power. El Cid was sent into exile in 1081, and then served several Moorish leaders who also made great use of his warfare art. (In his switching-sides attitude, one could notice that El Cid pioneered modern politics as well.)
At the turn of the 11th century, El Cid was followed by both Moorish and Christian troops. His plan to conquest the Kingdom of Valencia was successfully carried out in 1094; he lived there for five years until a Berber dynasty, the Almoravids, laid siege to the city. Because of the privations the siege implied, El Cid’s health state was deteriorating day after day… The Prince of Valencia, from his deathbed, requested his faithful subjects to come by his side and hear his last will.
After his death in 1099, in accordance with his requests, he was dressed in full armor and sat astride his horse, so that he could spearhead the last charge aimed at breaking the siege. The legend goes that as they saw El Cid leading the furious cavalry, his enemies, who had heard about his death, fled the battlefield in large numbers.
The Prince is dead; long(er) life the Prince!

Sources:
- https://en.wikipedia.org/wiki/El_Cid
- https://global.britannica.com/biography/the-Cid
- http://www.historynet.com/the-genius-of-el-cid.htm