section_path: Later life, illness, and death
section_name: Later life, illness, and death
paragraph_text: Later life, illness, and death
  
  Columbus had always claimed that the conversion of non-believers was one reason for his explorations, and he grew increasingly religious in his later years. Probably with the assistance of his son Diego and his friend the Carthusian monk Gaspar Gorricio, Columbus produced two books during his later years: a Book of Privileges (1502), detailing and documenting the rewards from the Spanish Crown to which he believed he and his heirs were entitled, and a Book of Prophecies (1505), in which passages from the Bible were used to place his achievements as an explorer in the context of Christian eschatology.
  
  In his later years, Columbus demanded that the Crown of Castile give him his tenth of all the riches and trade goods yielded by the new lands, as stipulated in the Capitulations of Santa Fe. Because he had been relieved of his duties as governor, the Crown did not feel bound by that contract and his demands were rejected. After his death, his heirs sued the Crown for a part of the profits from trade with America, as well as other rewards. This led to a protracted series of legal disputes known as the pleitos colombinos ("Columbian lawsuits").
  
  During a violent storm on his first return voyage, Columbus, then 41, had suffered an attack of what was believed at the time to be gout. In subsequent years, he was plagued with what was thought to be influenza and other fevers, bleeding from the eyes, temporary blindness and prolonged attacks of gout. The attacks increased in duration and severity, sometimes leaving Columbus bedridden for months at a time, and culminated in his death 14 years later.
  
  Based on Columbus's lifestyle and the described symptoms, some modern commentators suspect that he suffered from reactive arthritis, rather than gout. Reactive arthritis is a joint inflammation caused by intestinal bacterial infections or after acquiring certain sexually transmitted diseases (primarily chlamydia or gonorrhea). In 2006, Frank C. Arnett, a medical doctor, and historian Charles Merrill, published their paper in The American Journal of the Medical Sciences proposing that Columbus had a form of reactive arthritis; Merrill made the case in that same paper that Columbus was the son of Catalans and his mother possibly a member of a prominent converso (converted Jew) family. "It seems likely that acquired reactive arthritis from food poisoning on one of his ocean voyages because of poor sanitation and improper food preparation", says Arnett, a rheumatologist and professor of internal medicine, pathology and laboratory medicine at the University of Texas Medical School at Houston.
  
  Some historians such as H. Micheal Tarver and Emily Slape, as well as medical doctors such as Arnett and Antonio Rodríguez Cuartero, believe that Columbus had such a form of reactive arthritis, but according to other authorities, this is "speculative", or "very speculative".
  
  After his arrival to Sanlúcar from his fourth voyage (and Queen Isabella's death), an ill Columbus settled in Seville in April 1505. He stubbornly continued to make pleas to the Crown to defend his own personal privileges and his family's. He moved to Segovia (where the court was at the time) on a mule by early 1506, and, on the occasion of the wedding of King Ferdinand with Germaine of Foix in Valladolid, Spain, in March 1506, Columbus moved to that city to persist with his demands. On 20 May 1506, aged 54, Columbus died in Valladolid.