Kenwood House in 1914 was leased by the Grand Duke Michael Michaelovitch of Russia (a grandson of Tsar Nicholas).
The Duke and his family took a great interest in local affairs, becoming President of the Hampstead General Hospital (1912). In 1913, he presented a motor ambulance to the hospital, the first of its kind outside London City.
In July 1914, on the eve of war, the Grand Duke and family opened a new high diving board at Highgate Ponds, which it was hoped would be used for practice for The Olympic Games.
When war broke out, the Duke offered his home as a war hospital, while his daughters commenced a fund to provide warm gloves for the men of the British Expeditionary Force. The whole family involved themselves in charity work.
When the Zeppelin raids started in London air defence became necessary and a Mobile Anti-Aircraft Brigade was set up at Kenwood in November, 1915, commanded by Commander A. Rawlinson, RNVR.
The guns were 75mm French auto-cannons and 3 inch British guns, adapted for high angle firing, mounted on trailers or Lanela motor-lorries (see photograph)
Barracks were set up in the Stable Block, where themen, guns and search-lights were all housed.
They paraded on 5th December 1915 and consisted of 7 automobile guns, 2 mobile searchlights and 14 other motor vehicle, equipment and telephone system, etc. They were inspected by Admiral Sir Percy Scott, the unit at this time being completely run by the Navy.
In the stable barracks, the personnel slept in hammocks which were stored away each morning as on biard a ship.
The officers and men were given the use of cricket ground and golf course (South Meadow).
The guns were in action several times, going up to their emergency site at the top of Hampstead Heath (Parliament Hill).
The unit was moved to the Norfolk coast in the August of 1916.
At Kenwood,in November, 1916, King George and Queen Mary attended the wedding of the Duke's younger daughter, Countess Nada, to Prince George of Battenburg, elder brother of Earl Mountbatten.
In 1917, Kenwood became occupied by an American, Mrs William Leeds, who later married Prince Christopher of Greece.
The Grand Duke and his wife are both buried in Hampstead Cemetry at Fortune Green.