Question: Which house in London was destroyed by the Luftwaffe in 1940?

Context paragraphs:
Municipal Theatre of Corfu: The Municipal Theatre of Corfu (Greek: Δημοτικό Θέατρο Κέρκυρας ) was the main theatre and opera house in Corfu, Greece, from 1902 to 1943.  The theatre was the successor of the Nobile Teatro di San Giacomo di Corfù, which became the Corfu city hall.  It was destroyed during a Luftwaffe aerial bombardment in 1943.  During its 41-year history it was one of the premier theatres and opera houses in Europe with contributions to the Arts and to the history of the Balkans.

St Stephen Coleman Street: St. Stephen's Church, Coleman Street was a church in the City of London, at the corner of Coleman Street and what is now Gresham Street, first mentioned in the 13th century.  Destroyed in the Great Fire of London of 1666, it was rebuilt by the office of Sir Christopher Wren.  The church was destroyed again, by bombing in 1940, and was never rebuilt.

Old Devonshire House: Old Devonshire House at 48 Boswell Street, was located between Theobald's Road in Bloomsbury, and Queen Square, London.  William Cavendish, 3rd Earl of Devonshire had the house built in 1668 for his son, also called William Cavendish, who was MP for Derby at that time and eventually became 1st Duke of Devonshire in 1694.  This house was later sold by William Cavendish, 3rd Duke of Devonshire, who built Devonshire House in fashionable Piccadilly.  Major George Henry Benton Fletcher bought Old Devonshire House in 1932, to display his keyboard collection.  He donated the house and his collection to the National Trust in November 1937.  The house was destroyed in May 1941 by a Luftwaffe bombing raid on Holborn during the Blitz.  Most of his keyboard instruments had been evacuated to Gloucestershire before the raid.  These survived and are currently on display in Fenton House, Hampstead.

Hawker Hurricane in Yugoslav service: The Royal Yugoslav Air Force (VVKJ) operated the British Hawker Hurricane Mk I fighter aircraft from 1938 to 1941.  Between 1938 and 1940, the VVKJ obtained 24 Hurricane Mk I's from early production batches, marking the first foreign sale of the aircraft.  Twenty additional aircraft were built by Zmaj under licence in Yugoslavia.  When the country was drawn into World War II by the German-led Axis invasion of April 1941, a total of 41 Hurricane Mk I's were in service as fighters.  They achieved some successes against "Luftwaffe" aircraft, but all Yugoslav Hurricanes were destroyed or captured during the 11-day invasion.

Operation Paula: Unternehmen Paula (Undertaking or Operation Paula) is the German codename given for the Second World War "Luftwaffe" offensive operation to destroy the remaining units of the "Armée de l'Air" (ALA), or French Air Force during the Battle of France in 1940.  On 10 May the German armed forces ("Wehrmacht") began their invasion of Western Europe.  By 3 June, the British Army had withdrawn from Dunkirk and the continent in Operation Dynamo, the Netherlands and Belgium had surrendered and most of the formations of the French Army were disbanded or destroyed.  To complete the defeat of France, the Germans undertook a second phase operation, "Fall Rot" (Case Red), to conquer the remaining regions.  In order to do this, air supremacy was required.  The "Luftwaffe" was ordered to destroy the French Air Forces, while still providing support to the German Army.

German bombing of Rotterdam: The German bombing of Rotterdam, also known as the Rotterdam Blitz, was the aerial bombardment of Rotterdam by the "Luftwaffe" on 14 May 1940, during the German invasion of the Netherlands in World War II.  The objective was to support the German troops fighting in the city, break Dutch resistance and force the Dutch to surrender.  Even though preceding negotiations resulted in a ceasefire, the bombardment took place nonetheless, in conditions which remain controversial, and destroyed almost the entire historic city centre, killing nearly 900 people and making 85,000 others homeless.

The Blitz: The Blitz was a German bombing offensive against Britain in 1940 and 1941, during the Second World War.  The term was first used by the British press as an abbreviation of "Blitzkrieg" (lightning war).  The Germans conducted mass air attacks against industrial targets, towns and cities, beginning with raids on London towards the end of the Battle of Britain in 1940, a battle for daylight air superiority between the "Luftwaffe" and the Royal Air Force over the United Kingdom.  By September 1940, the "Luftwaffe" had failed and the German air fleets ("Luftflotten") were ordered to attack London, to draw RAF Fighter Command into a battle of annihilation.  Adolf Hitler and "Reichsmarschall" Hermann Göring, commander-in-chief of the "Luftwaffe", ordered the new policy on 6 September 1940.  From 7 September 1940, London was systematically bombed by the "Luftwaffe" for 56 out of the following 57 days and nights.  Most notable was a large daylight attack against London on 15 September.

Forthbank Park: Forthbank Park was a sports venue in Stirling, Scotland until 1940.  Forthbank park was home to King's Park F.C. until the beginning of World War II.  During the war Forthbank was destroyed by the Luftwaffe.  The ground was victim to the only German bomb strike on the town during the conflict.  The majority of the stadium was damaged beyond financial repair by King's Park and was demolished.  Shortly after the war King's Park closed down permanently.

Montagu House, Portman Square: Montagu House at 22 Portman Square was a historic London house.  Occupying a site at the northwest corner of the square, in the angle between Gloucester Place and Upper Berkeley Street, it was built for Mrs Elizabeth Montagu, a wealthy widow and patroness of the arts, to the design of the neoclassicist architect James Stuart.  Construction began in 1777 and the house was completed in 1781, whereupon it became Mrs Montagu's London residence until her death on 25 August 1800.  The house was destroyed by an incendiary bomb in the Blitz of London and the site is now occupied by the Radisson SAS Portman Hotel.

1940 Football League War Cup Final: The 1940 Football League War Cup Final was contested by West Ham United and Blackburn Rovers.  It was played on 8 June 1940 and kicked-off at 6.30pm despite fears that London would be bombed by the Luftwaffe.  The wartime crowd included wounded members of the BEF recently evacuated from Dunkirk.  West Ham won the tie 1–0; the only goal coming from Sam Small in the 34th minute when he followed up a parried shot from George Foreman.

Supporting paragraphs: Montagu House, Portman Square The Blitz
Answer: Montagu House