Mieczysław Małecki (14 July 1903 – 3 September 1946) was a Polish linguist.
 Professor at the Jagiellonian University in Kraków, during World War II under a cover of collaboration with the Nazi-run "Institut für Deutsche Ostarbeit" he in fact, with support of the Polish Underground State, used his position to organize much of the Polish underground education in occupied Kraków.
 He resumed his post at the Jagiellonian University after the war, although he died shortly afterwards (in 1946).
The Home Army Museum in Kraków (Polish: "Muzeum Armii Krajowej w Krakowie" ) was created in Kraków, Poland in 2000, to commemorate the struggle for independence by the underground Polish Secret State and its military arm Armia Krajowa (The Home Army), the largest resistance movement in occupied Europe during World War II.
 The Museum is named after general Emil August Fieldorf ”Nil”.
 It is the only such institution in Poland promoting knowledge about the Polish Underground State and its armed forces during World War II.
 The idea behind the Home Army Museum is to provide a holistic picture of the Polish underground, its spiritual origins and the shape of patriotic heritage to the present day.
Kamienie na szaniec (lit.
 "Stones for the Rampart", also translated as Stones on the Barricade) is a 1943 non-fiction novel by Polish writer Aleksander Kamiński.
 Published by the Polish underground press during the World War II occupation of Poland, the book describes the acts of sabotage and armed resistance carried out by the Polish underground scout movement, the Gray Ranks, of whom Kamiński was one of the instructors and leaders.
Polish Ecumenical Council (Polish: "Polska Rada Ekumeniczna" ) founded in 1946 to promote interchurch cooperation includes nearly all churches except the Polish Catholic Church.
 In 1989 member churches included the Orthodox, Lutheran, Methodist, Baptist, Reformed, and Old Catholic.
 Cooperation with the Polish Catholic Church began in 1974 when the council established a Combined Ecumenical Commission to deal with the analogous ecumenical commission of the Polish Catholic Bishops' Conference.
 In 1977 the council named a subcommittee for discussion of individual theological questions; by 1980 bilateral dialogs had begun among members sharing similar doctrine.
 Given Poland's history of religious tolerance, the restoration of religious freedom in 1989 was expected to expand the tentative ecumenical contacts achieved during the communist era.
The Polish Underground State (Polish: "Polskie Państwo Podziemne" , also known as the Polish Secret State) is a collective term for the underground resistance organizations in Poland during World War II, both military and civilian, that were loyal to the Government of the Republic of Poland in exile in London.
 The first elements of the Underground State were established in the final days of the German invasion of Poland that began in September 1939.
 The Underground State was perceived by supporters as a legal continuation of the pre-war Republic of Poland (and its institutions) that waged an armed struggle against the country's occupying powers: Nazi Germany and the Soviet Union.
 The Underground State encompassed not only military resistance, one of the largest in the world, but also civilian structures, such as education, culture and social services.
Matylda Getter (1870–1968) was a Polish Catholic nun, mother provincial of CSFFM (lat.
 "Congregatio Sororum Franciscalium Familiae Mariae") - Franciscan Sisters of the Family of Mary in Warsaw and social worker in pre-war Poland.
 In German-occupied Warsaw during World War II she cooperated with the famous Irena Sendler and the Żegota resistance organization in saving the lives of hundreds of Jewish children from the Warsaw Ghetto.
 She was recognized as one of Polish Righteous among the Nations by Yad Vashem organisation.
 for her rescue activities.
The Home Army (Polish: "Armia Krajowa" ; ] , abbreviated AK) was the dominant Polish resistance movement in Poland occupied by Nazi Germany and the Soviet Union during World War II.
 It was formed in February 1942 from the "Związek Walki Zbrojnej" (Armed Resistance).
 Over the next two years, it absorbed most other Polish underground forces.
 Its allegiance was to the Polish Government-in-Exile, and it constituted the armed wing of what became known as the "Polish Underground State".
Irena Sendler (née Krzyżanowska ), also referred to as "Irena Sendlerowa" in Poland, "nom de guerre" "Jolanta" (15 February 1910 – 12 May 2008), was a Polish nurse, humanitarian, and social worker who served in the Polish Underground during World War II in German-occupied Warsaw, and was head of the children's section of Żegota, the Polish Council to Aid Jews (Polish: "Rada Pomocy Żydom" ), which was active from 1942 to 1945.
Maria Aniela Fedecka - (1904, Moscow - 21 December 1977, Warsaw) - was a Polish social worker, member of Workers' Defence Committee.
 During World War II she was an activist in the Polish Underground and Polish anti-Holocaust resistance in Wilno (now Vilnius, Lithuania).
 During German occupation she helped save many Jewish children as well as the poverty-stricken peasants of Lebioda, her husband's hometown situated near Lida (now in Belarus).
 In 1987, Maria Fedecka was honoured by Yad Vashem as Righteous among the Nations for the help she had brought to Jewish children and their families.
Mary Braganza, popularly known as Karuna Mary, is an Indian Catholic nun, educationist, social worker, writer, a promoter of developmental education and a former Principal of Sophia College, Mumbai.
 She is a member of the Society of the Sacred Heart (RSCJ) and is a former head of 204 colleges managed by the Order.
 It was during her tenure at Sophia College, the institution started Sophia Polytechnic in 1970.
 The Government of India awarded her the fourth highest civilian honour of the Padma Shri, in 2008, for her contributions to society.

Question: A Polish Catholic nun cooperated with Polish nurse, humanitarian, and social worker who served in the Polish Underground in what war?
Answer: World War II