Hernán Cortés de Monroy y Pizarro, 1st Marquis of the Valley of Oaxaca (Spanish pronunciation: [erˈnaŋ korˈtes de monˈroj i piˈθaro]; 1485 – December 2, 1547) was a Spanish Conquistador who led an expedition that caused the fall of the Aztec Empire and brought large portions of mainland Mexico under the rule of the King of Castile in the early 16th century. Cortés was part of the generation of Spanish colonizers that began the first phase of the Spanish colonization of the Americas.

Born in Medellín, Spain, to a family of lesser nobility, Cortés chose to pursue a livelihood in the New World. He went to Hispaniola and later to Cuba, where he received an encomienda and, for a short time, became alcalde (magistrate) of the second Spanish town founded on the island. In 1519, he was elected captain of the third expedition to the mainland, an expedition which he partly funded. His enmity with the Governor of Cuba, Diego Velázquez de Cuéllar, resulted in the recall of the expedition at the last moment, an order which Cortés ignored. Arriving on the continent, Cortés executed a successful strategy of allying with some indigenous peoples against others. He also used a native woman, Doña Marina, as an interpreter; she would later bear Cortés a son. When the Governor of Cuba sent emissaries to arrest Cortés, he fought them and won, using the extra troops as reinforcements. Cortés wrote letters directly to the king asking to be acknowledged for his successes instead of punished for mutiny. After he overthrew the Aztec Empire, Cortés was awarded the title of Marqués del Valle de Oaxaca, while the more prestigious title of Viceroy was given to a high-ranking nobleman, Antonio de Mendoza. In 1541 Cortés returned to Spain, where he died peacefully but embittered, six years later.

Ivan IV Vasilyevich (Russian:  Ива́н Четвёртый, Васи́льевич​ (help·info), Ivan Chetvyorty, Vasilyevich; 25 August 1530 – 28 March [O.S. 18 March] 1584), known in English as Ivan the Terrible (Russian:  Ива́н Гро́зный​ (help·info), Ivan Grozny; lit. Fearsome), was Grand Prince of Moscow from 1533 until his death. His long reign saw the conquest of the Khanates of Kazan, Astrakhan, and Siberia, transforming Russia into a multiethnic and multiconfessional state spanning almost one billion acres, approximately 4,046,856 km² (1,562,500 sq mi). Ivan managed countless changes in the progression from a medieval state to an empire and emerging regional power, and became the first ruler to be crowned as Tsar of all Russia.

Historic sources present disparate accounts of Ivan's complex personality: he was described as intelligent and devout, yet given to rages and prone to episodic outbreaks of mental illness. On one such outburst Tsar beat and unpremeditatedly killed his groomed and chosen heir Ivan Ivanovich. This led Tsardom to be passed to Tsar's younger son: the weak and intellectually disabledFeodor I of Russia. Ivan's legacy is complex: he was an able diplomat, a patron of arts and trade, founder of the Russia's first Print Yard, but he is also remembered for his paranoiac suspiciousness and cruel persecution of nobility.