St. John of the Cross died on December 14, 1591, at the age of 49, from a severe skin infection in his foot that spread to his bones and ultimately caused fatal blood poisoning. His final months were marked by painful, gangrenous sores, primitive surgical attempts that likely worsened his condition, and deliberate neglect by the prior of the monastery where he spent his last weeks.
The Infection That Killed Him
A 2017 medical analysis published in PubMed concluded that St. John of the Cross developed cellulitis, a deep skin infection, in his foot. The infection progressed into a cutaneous abscess, meaning pus collected beneath the skin as the tissue began to die. Without antibiotics or sterile surgical tools, the bacteria burrowed through deeper layers of tissue and eventually reached the bones of his leg, a condition called osteomyelitis. From there, the infection entered his bloodstream, causing the sepsis that killed him.
The visible symptoms would have been severe. His foot and lower leg swelled, turned red, and became intensely painful. The skin broke down into open, weeping sores that turned gangrenous, meaning the tissue was actively dying and decaying. Fever accompanied the infection throughout, growing worse as the bacteria spread.
His Final Months: From La Peñuela to Úbeda
In the summer of 1591, John had been stripped of all his leadership positions within the Discalced Carmelite order. A general chapter meeting in Madrid that June left him without office, and he was sent to a remote house at La Peñuela in southern Spain to prepare for a possible assignment to Mexico. He arrived in August. Within weeks, severe fevers set in, and the infection in his foot became debilitating.
On September 22, too ill to remain at La Peñuela, he traveled to the nearby city of Úbeda, where there was a larger Carmelite monastery with better resources. He would spend nearly three months there, slowly deteriorating, before dying on December 14.
Neglect and Mistreatment at Úbeda
The prior at the Úbeda monastery, Friar Francisco Crisóstomo, treated John with open hostility. Rather than ensuring the sick friar received care, Crisóstomo denied him medical attention. Historical accounts describe outright abuse and mistreatment during this period. John had fallen out of political favor within the order after years of conflict over reform, and Crisóstomo apparently felt no obligation to care for him. The neglect almost certainly accelerated the progression of his infection during the critical weeks when intervention might have made a difference.
Surgical Attempts That May Have Made Things Worse
At some point during his illness, surgeons did intervene. They cut away the dead and rotting tissue from his leg and cauterized the open sores, pressing heated instruments against the wounds to try to stop the spread of infection and the buildup of toxins in his body. These were standard techniques in 16th-century Spain, but they were performed without any understanding of antiseptic procedure.
The medical analysis of his case suggests the surgery itself may have helped the bacteria spread deeper. Cutting into infected tissue with unsterilized instruments could easily have opened new pathways for the infection to reach bone and blood. In the researchers’ assessment, it is “not unconceivable” that the surgical intervention promoted the secondary sepsis that killed him. What was meant to save his life likely hastened his death.
His Last Hours
By mid-December, the infection had overwhelmed his body. His last recorded words were “Lord, into thy hands I commend my soul,” echoing the words of Christ on the cross as recorded in the Gospel of Luke. He died just before midnight on December 14, 1591.
What Happened to His Body
John was buried at Úbeda, but his remains did not stay there long. In 1593, at the request of the Carmelite monastery in Segovia where John had previously lived, his body was secretly exhumed and moved to Segovia. The monastery at Úbeda, understandably unhappy about losing the remains, protested. A compromise was eventually reached: Úbeda received one leg and one arm, while another arm had already been removed as the body passed through Madrid, kept there as a relic. Segovia retained his head and torso.
Those remains were venerated openly at Segovia until 1647, when Rome ordered them buried to prevent unauthorized veneration. They stayed underground until the 1930s, when they were disinterred and placed in a marble case above a special altar in a side chapel at the Convent of the Discalced Carmelites in Segovia, where they remain today.