Gen Franco ruled Spain following the civil war until his death in 1975
A new book claims the Spanish dictator, General Francisco Franco, may have had more in common with Adolf Hitler than previously known - having one testicle.
Much like the Nazi leader, Franco's loss stemmed from an injury he suffered in battle, his doctor's granddaughter told the historian Jose Maria Zavala.
Franco was wounded in the lower abdomen at El Biutz, near Ceuta, in June 1916.
Biographers have long speculated this affected the reproductive organs of the dictator, who ruled from 1939 to 1975.
However, he did have a daughter, Carmen Franco y Polo, in 1926.
Last year, documents came to light containing an account by a medic who treated Hitler during the Battle of the Somme in 1916.
Dr Johan Jambor told his priest that Hitler had been injured in the abdomen and had lost a testicle. He said the first question Hitler had asked him was: "Will I be able to have children?"
In his new book, Mr Zavala quotes Dr Ana Puigvert as recalling that her grandfather, Antonio Puigvert, a urologist known to have had Franco as a patient, had told her the dictator had confided in him.
"Franco was monorchid - he had only one testicle," she said.
Franco was a captain in the Spanish army when, in late June 1916, he was shot in the lower abdomen while defending the modern-day Spanish enclave of Ceuta on Morocco's Mediterranean coast.
In 1936, he joined the military uprising that led to the Spanish Civil War and assumed leadership of the fascist Falange Party.
Three years later, with the aid of Nazi Germany and fascist Italy, he won the war and established a dictatorship. Franco kept Spain neutral during World War II, after which he declared Spain a monarchy with himself as regent.
In 1969, he announced that on his death he would be succeeded by Juan Carlos I, grandson of Spain's last reigning king, hoping that he would maintain his regime.
However, after his death in 1975, the new king moved to dismantle the authoritarian institutions and restore democratic rule.