Frederica of Hanover (Friederike Luise; Greek: Φρειδερίκη, romanized: Freideríki Luísa; 18 April 1917 – 6 February 1981) was Queen of Greece from 1 April 1947 until 6 March 1964 as the wife of King Paul and the Queen Mother of Greece from 6 March 1964, when her son Constantine II became King, until 8 December 1974, when the monarchy was officially abolished after a referendum.

Granddaughter of Kaiser Wilhelm II and daughter of Duke Ernest Augustus of Brunswick, Frederica was born a few months before the fall of the German Empire.

In the period of civil war that followed, Frederica developed a strong social activity to support the efforts of the government and the Crown.

She organised a network to help refugees affected by the forces of the Democratic Army, creating the so-called "children's towns", an initiative that was widely criticised by opponents of the Crown.

However, according to the prevailing historiographical view, she continued to influence the fate of the country through her son, now King Constantine II.

Frederica was widely regarded as Constantine's éminence grise and continued to be attacked by the opposition, who blamed her for the tensions between the palace and the government of George Papandreou (1964–1965).

[5] In 1934, Adolf Hitler, in his ambition to link the British and German royal houses, asked for Frederica's parents to arrange for the marriage of their seventeen-year-old daughter to the Prince of Wales.

Moreover, the age difference was too great (the Prince of Wales was twenty-three years Frederica's senior), and her parents were unwilling to "put any such pressure" on their daughter.

Their engagement was announced officially on 28 September 1937, and Britain's King George VI gave his consent pursuant to the Royal Marriages Act 1772 on 26 December 1937.

[2] Frederica became Hereditary Princess of Greece, her husband being heir presumptive to his childless elder brother, King George II.

[10][11] At the peak of World War II, in April 1941, the Greek royal family was evacuated to Crete in a Sunderland flying boat.

[13] When she was in London representing her sick husband at the wedding of his first cousin Prince Philip of Greece and Denmark to King George VI's elder daughter Princess Elizabeth in November 1947, Winston Churchill remarked on the Kaiser being her grandfather.

The King and Queen took this opportunity to strengthen the monarchy, and paid official visits to Marshal Josip Broz Tito in Belgrade, Presidents Luigi Einaudi of Italy in Rome, Theodor Heuss of West Germany, and Bechara El Khoury of Lebanon, Emperor Haile Selassie I of Ethiopia, Governor-General Chakravarthi Rajagopalachari of India, King George VI of the United Kingdom, and the United States as guest of President Dwight D. Eisenhower.

However, at home in Greece and abroad in the United Kingdom, Queen Frederica was targeted by the opposition, because as a girl she had belonged to the Bund Deutscher Mädel (League of German Girls), a branch of the Hitler Youth group for young women; her supporters argued that evading membership in the group would be difficult under the existing political climate in Nazi Germany at the time.

[18] This was due to a string of reasons that included her political interference, her intemperate character, her German ethnicity, and the fact she became identified in the public consciousness with all that was reactionary.

When her son, King Constantine II, married Princess Anne-Marie of Denmark later that year on 18 September, Queen Frederica stepped back from the majority of her public duties in favor of her daughter-in-law.

King Constantine II's clashes with the democratically elected Prime Minister George Papandreou Sr. were blamed by critics for causing the destabilisation that led to a military coup on 21 April 1967 and the rise of the regime of the colonels.

A plebiscite was held on 8 December 1974 in which Constantine (who was able to campaign only from outside the country) freely admitted past errors, and promised to support democracy.