Guérisse was born in
Brussels, and qualified in medicine at the
Université Libre de Bruxelles before joining the
Belgian Army. Guérisse was Médecin-Capitaine with a Belgian cavalry regiment during their eighteen-day campaign in May 1940. He managed to escape to England through
Dunkirk. At
Gibraltar, he joined the crew of a former French merchant ship,
Le Rhin, which was later renamed and served in the Mediterranean on clandestine missions. He secured entry into the British
Royal Navy and was commissioned as Lieutenant Commander Patrick Albert O'Leary RNVR of French-Canadian origin. The "Canadian" identity attempted to explain his not-quite British accent in English, and his not-quite French accent in French, in order to protect his family in occupied Belgium if he was captured. He had a six-week undercover training session with Naval Intelligence. Until April 1941, he was serving mainly as a conducting officer, escorting agents ashore in small boats through the surf, whilst the large vessel lay some distance offshore. This was skilled work, exposed to physical dangers from the sea-conditions and operational dangers from the Vichy security services. On 25 April 1941, during a mission to place
Special Operations Executive (SOE) agents in
Collioure, on
Roussillon coast in southern France, "O'Leary" and three crewmen from HMS
Fidelity were arrested by the
Vichy French coast guard and taken to a camp for British military prisoners at
Saint-Hippolyte-du-Fort near
Nîmes. Helped by 'fellow British' officers, "O'Leary" escaped in early June 1941. He went to
Marseille where there was an escape organisation run by a British Army officer,
Ian Grant Garrow, and soon made contact. At this point his intention was make his way to Gibraltar and resume his original naval service. Events were to dictate otherwise because Garrow wanted "O'Leary" to stay and help with the organisation since he had undercover training and, unlike Garrow, spoke French fluently. Consequently, a request was sent to London that he stay, which was approved and confirmed by a
BBC radio message received on 2 July 1941. "O'Leary" immediately began his job : within a four-month period, he helped about fifty men escape from the prison of St Hippolyte du Fort, then moved them down the line back to England through the
Pyrenees. When the Vichy France authorities captured Garrow in October 1941, Guérisse took over as chief of the escape network. Along with others, including
Nancy Wake, he smuggled a guard uniform to Garrow in his cell in
Mauzac prison camp, which helped Garrow's escape on 6 December 1942. At this point the British decided it was time for Garrow to return to London, so "O'Leary" continued in command and expanded the reach of the escape line's operations. The line carried over 600 escapees to Spain and back to Britain. In January 1943, the escape line was infiltrated and betrayed by a French turncoat, Roger le Neveu; Guérisse was arrested in
Toulouse on 6 March 1943. En route to prison he managed to get one of the younger members, Fabien de Cortes, to escape and warn the British. After his arrest the line was taken over by
Marie Dissard. Guérisse told nothing to the
Gestapo interrogators even while being tortured. He then was sent to a series of concentration camps, including
Mauthausen. No one, neither in the network, nor the French police nor the Gestapo, ever knew "O'Leary's" true identity. In the summer of 1944, he was at the
Natzweiler-Struthof concentration camp in
Alsace with another SOE agent,
Brian Stonehouse. At the camp he witnessed the arrival of four other female SOE agents,
Andrée Borrel,
Vera Leigh,
Diana Rowden, and
Sonya Olschanezky, who were all executed and disposed of in the
crematorium in an attempt to make them disappear without a trace, under the
"Night and Fog" programme. After the war, Guérisse and Stonehouse were able to testify at the
Nazi war crimes trials as to the women's fate. Finally, Guérisse was taken to the
Dachau concentration camp, tortured again and then sentenced to death. However, when
SS guards surrendered before the Allied advance, Guérisse took command and refused to leave until the Allies agreed to take care of the inmates. On 30 April 1945, he was chosen as the first president of the International Prisoners' Committee that administered the camp after liberation. Pat O'Leary (i.e. Albert Guérisse) Mauthausen Arolsen Archives DocID1582970.jpg|Registration form of "Patrick O'Leary" as a prisoner at Mauthausen Pat O'Leary (i.e. Albert Guérisse) Natzweiler Arolsen Archives DocID3195554.jpg|List of personal effects at Natzweiler Pat O'Leary (i.e. Albert Guérisse) Arolsen Archives DocID86334889.jpg|Request (stamped "SECRET") for his repatriation after the liberation of Dachau Pat O'Leary (i.e. Albert Guérisse) Arolsen Archives DocID86334888.jpg|Worksheet on the request for the repatriation of "Patrick Albert O'Leary" (labelled "
VIP") Pat O'Leary (i.e. Albert Guérisse) Arolsen Archives DocID86334890.jpg|Report (stamped "SECRET") on his repatriation From its founding in 1956 until his death he served many terms as president of the Comité International de Dachau, and regularly gave the keynote speech at the May memorial ceremonies. In 1946, he was appointed a member of the War Crime Commission at Nuremberg. In November 1946 he was demobilized from the Royal Navy and resumed his real name and rejoined the Belgian Army, returning to his former regiment. In 1951, he volunteered as a medical officer for the Belgian United Nations Corps in Korea during the
Korean War where he was wounded while going to rescue a wounded soldier under enemy fire. He became the head of the medical service of the Belgian Army and retired in 1970, in the rank of
major general. ==Personal life==