This decade saw the foundation and construction of Casa Loma, Sir Henry's command of the 6th Infantry Brigade, and the years of the First World War.
- 1910. Foundation of Casa Loma laid on Davenport Hill.
- 1910. Sir Henry pays for the trip of 600 members of the QOR to England to take part in war games in Aldershot.
- 1910, June 18 to June 24. Week long Jubilee celebrations to celebrate the 50th Anniversary of the Queen's Own.
- 1910, September 13. QOR arrived in London.
- 1910, May 10. Funeral of King Edward VII.
- 1910. Sir Henry became a Companion of the Victorian Order.
- 1910. Combines Investigation Act enacted.
- 1910, September 10. It became known that some QOR officers on the trip to England had typhoid.
- 1910, September 12. Sir Henry visited with the King at Balmoral Castle.
- 1910, September 24. One of the QOR officers, Roy Gzowski, dies.
- 1911. Construction started on Casa Loma.
- 1911–1912. Pellatt incorporated three land companies: Home City Estates, Toronto City Estates, British Colonial Land and Securities.
- 1911, June 22. Sir Henry and his wife are present at the Coronation of King George V.
- 1911, April. Sir Henry retired from active command of the QOR.
- 1912. Created a Knight of Grace in the Venerable Order of St. John of Jerusalem.
- 1912, July 24. Lady Pellatt warranted as Chief Commissioner of the Girl Guides and travelled across the country drumming up interest for the Baden Powell Girl Guides.
- 1912, October. Pellatt goes out west for business and pleasure.
- 1912. Sir Henry appointed to command the 6th Infantry Brigade. His tenure of command extended a number of times until February 10th, 1919.
- 1913, March. Casa Loma opened for guides tea.
- 1913, June 29. Marriage of Frederick Mill Pellatt to Victoria Blakely.
- 1913. There was major loss of life and shipping on the Great Lakes after a severe storm.
- 1914. Major part of Casa Loma structure finished.
- 1914, August 4. Belgium invaded and Great Britain declared war against Germany.
- 1915, December 1. Sir Henry appointed Honourary Lieutenant-Colonel 2nd Battalion QOR.
- 1915, February 15. Lady Pellatt elevated to the rank of Lady of Grace in the Order of St. John of Jerusalem.
- 1915, September 25. Canadian Girl Guides Rally and Garden Fete held at Casa Loma.
- 1916. Sir Henry became president of the Mining Corporation of Canada.
- 1916, July 13. Sir Henry was promoted to the rank of temporary Brigadier-General.
- 1916. Formation of Toronto City Estates, the property development beside Casa Loma.
- 1916. Election of Unionist Government.
- 1917, June 23. Annual Rally at Casa Loma.
- 1917, March 17. Tea held in the Conservatory of Casa Loma.
- 1918. Sir William Mackenzie's Canadian Northern was taken over by the government.
- 1918, August 29. Henry B. Holland died.
- 1919. Sir Robert Baden-Powell and Lady Baden-Powell visited Canada. A scout rally was held at Casa Loma in May.
- 1919. HRH Prince of Wales visited Canada and met with the Pellatts.
- 1919, May. Lady Pellatt received the Silver Fish of Guides in honour of her steady work with Guides and Brownies.
Continue the story with the next decade of Sir Henry Pellatt's life, 1920–1930, or return to the full timeline highlights.