William Hargreaves (1880–1941) was an English composer, mainly of songs for the music hall. His most famous composition was Burlington Bertie From Bow in 1916 but he also wroteDelaney's Donkey, I Know Where the Flies Go, PC 49, We All Went Marching Home Again, They Built Piccadilly For Me and Give My Regards to Leicester Square.

Hargreaves is also sometimes credited with several songs for Billy Williams, including Postcards (1908); and I Must Go Home Tonight (1909).

His It’s The Old Army Game was added to the originally American musical Poppy when it was performed in London stage in 1924.

He was married to Ella Shields.

Source: Wikipedia