In November 1854, William Banks was Sergeant-Major of Field Battery 'H' with the Royal Artillery, then engaged at the Battle of Inkerman where he had his horse shot from under him.

Following the battle, Brigadier-General Sir Richard Dacres, sanctioned by Field-Marshal Lord Raglan, recommended him for a commission arising from an act of "distinguished conduct in the field".

Having started his career in 1838 as a gunner, William Banks rose to brevet major and was retired on full pay in 1872 with the honorary rank of lieutenant colonel, 97th Regiment of Foot – a considerable achievement for the time.

War Office records provide insight into the effort by which both father and son sought to further young Joseph's military ambitions.

In 1860, his father (then a captain) sought to obtain for him a commission, with or without purchase, both within the regular British army and with a colonial regiment, but he was turned down in both cases.

In 1862, Joseph sat and passed his entry exams to the Royal Military College, Sandhurst, but did not attend, probably due to the family's inability to find the funds to send him there.

Despite these best efforts to gain a commission, in December 1864, Banks was forced to enlist as a private soldier with the 17th Royal Lancers (known as the "Duke of Cambridge's Own").

His father then again sought to further the career of his son by apparently invoking the interest of the commander-in-chief, Prince George, Duke of Cambridge, in the process.

Something worked, and Colonel Drury Curzon Drury-Lowe, the commander of the 17th Lancers who had just promoted "this fine young soldier" to sergeant, was able to recommend him for a commission two months later.

With the 7th Dragoons, he took part in the 1882 Egyptian Campaign, serving on Lord Kitchener's staff as brigade major to the cavalry in the Army of Occupation at Egypt.

He enjoyed several other staff and regimental appointments, including that of musketry instructor to the Dragoon Guards and officiating assistant adjutant-general of the Bombay Army under Field Marshal Lord Roberts V.C.

As commander of the 6th New Zealand Mounted Rifles, Colonel Banks led this troop into action at the Transvaal and the Orange River Colony.

In August 1901, Lord Kitchener, on whose staff Banks had served as brigade major in Egypt, requested that he take temporary command of Remounts until rejoining the 6th Mounted Rifles for their return to New Zealand in May 1902.

On 9 September 1876, at the Church of St. Nicholas in Chadlington, Oxfordshire, then Lieutenant Joseph Henry Banks married (Frances) Edith Carter (1854–1950).

Though ordered to do so, during the Blitz Mrs Banks refused to move from her cottage and proudly collected bomb shrapnel from her garden for her grandchildren.