Mervyn Napier Waller was born on 19 June 1893 at Penshurst, Victoria. In August 1915 he enlisted with the 22nd Battalion, AIF, and trained at the Royal Park Camp in Victoria before subsequently being transferred to the artillery. In May 1916, he embarked on HMTS Medic to England via Durban to complete his military training on Salisbury Plain.

At the end of 1916 he left for active service in France, serving with the 111th Howitzer Battery, 4th Division. During his service, Waller used his diary to make sketches. He took part in a number of battles before being severely wounded in May 1917 at Bullecourt. Waller’s right arm had to be amputated at the shoulder and during his convalescence in France and England, he learnt to draw and write with his left hand.

He returned to Australia in November 1917 and completed a series called 'War sketches in black and white, watercolour and oil', mostly done while on active service and in camp. Some were made after his injury and based on earlier sketches. These works were exhibited in 1918 and 1919 in Melbourne, Sydney, Adelaide, and Hobart.

In 1937 the Australian War Memorial invited Waller to submit designs for the proposed stained glass windows and mosaics for the Hall of Memory. Waller was selected to design and install the mosaic on the basis of his reputation as a large-scale mural artist and mosaicist. His service in the First World War was also considered important. The windows were completed in 1951 and the mosaics by 1958.

In January 1958, Waller married Lorna Marion Reyburn, an artist in her own right, who assisted Waller in some of his projects. He was appointed an Officer of the Order of the British Empire (O.B.E) in 1953 and a Companion of the Order of St Michael and St George (C.M.G) in 1959 for his work. Waller died at Ivenhoe, Melbourne on 30 March 1972.