The Kotwica was first painted on walls in Warsaw, as a psychological-warfare tactic against the occupying Germans, by Polish boy scouts on March 20, 1942. On June 27, 1942, a new tradition was born: to commemorate the patron saint's day of Polish President Władysław Raczkiewicz and Commander-in-Chief Władysław Sikorski, members of the Armia Krajowa stamped several hundred copies of the German-backed propaganda newspaper “The New Warsaw Courier”, with the Kotwica. Initially, only 500 copies were so stamped; the following year, the number reached 7,000.
On February 18, 1943, the AK commander, General Stefan Rowecki, issued an order specifying that all sabotage, partisan and terrorist actions be signed with the Kotwica. On February 25, the official organ of the Armia Krajowa, Biuletyn Informacyjny, called the Kotwica "the sign of the underground Polish Army". Soon the symbol gained enormous popularity and became recognized by most Poles. During the later stages of the war, most of the political and military organizations in Poland (even those not related to Armia Krajowa) adopted it as their symbol. It was painted on the walls of Polish cities, stamped on German banknotes and post stamps, printed in the headers of the underground newspapers and books, and it became one of the symbols of the Warsaw Uprising.
After World War II, Poland's communist authorities banned the Kotwica. Used by most associations of former Armia Krajowa members in exile, it was strictly prohibited in Poland. As the communist grip weakened, the symbol was no longer censored, and in 1976 it became one of the symbols of Ruch Obrony Praw Człowieka i Obywatela (ROPCiO), an anti-communist organization defending human rights in Poland. Later it was also adopted by various other anti-communist political organizations, ranging from the rightist Konfederacja Polski Niepodległej (KPN) to the leftist Solidarność Walcząca (Fighting Solidarity).
Armia Krajowa (the Home Army, literally translated as the Country's Army), abbreviated "AK", was the dominant Polish resistance movement in World War II German-occupied Poland. It was formed in 1939 and over the next 2 years absorbed most other Polish underground forces. It was loyal to the Polish government in exile and constituted the armed wing of what became known as the "Polish Underground State". Estimates of its membership in 1944 range from 200,000 to 600,000, with the most common number being 400,000; that figure would make it not only the largest Polish underground resistance movement but among the two largest in Europe during World War II. It was disbanded on January 19, 1945, when Polish territory had largely been cleared of German forces by the advancing Soviet Red Army.
Polish Underground State (Polish: Polskie Państwo Podziemne, also known as Polish Secret State) refers to all underground resistance organizations in Poland during World War II, both military and civilian, loyal to the Polish Government in Exile in London. The Underground State was a legal continuation of the pre-war Republic of Poland and its institutions, in armed struggle against the occupying powers (Nazi Germany and the Soviet Union). Polish historian Stanisław Salmonowicz defined it as a "collection of state-legal, organizational and citizenship structures, which were to ensure constitutional continuation of Polish statehood on its own territory. This constitutional continuity, real performance of state's functions on its past territory and loyalty of a great majority of the Polish society to it were the most significant elements of its existence." The government in exile, based in London, with President of Poland and Commander-in-Chief of the Polish Army was the top military and civilian authority, recognized by the authorities of the Underground state as their commanders.