The 4th Mounted Division was a short-lived British cavalry division composed of Yeomanry

Yeomanry

Yeomanry is a designation used by a number of units or sub-units of the British Territorial Army, descended from volunteer cavalry regiments. Today, Yeomanry units may serve in a variety of different military roles.-History:...

 and Territorial Force

Territorial Force

The Territorial Force was the volunteer reserve component of the British Army from 1908 to 1920, when it became the Territorial Army.-Origins:...

 units during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

.

It was formed on 20 March 1916 from three existing second line mounted brigades and the newly formed 2/1st Southern Mounted Brigade. In July 1916 the yeomanry regiments were dismounted and their horses sent to remount depots. The regiments then converted to yeomanry cyclist regiments, and the division was then renamed the 2nd Cyclist Division. The division was broken up in November 1916, having remained in England on Home Defence duties.

Order of Battle March 1916

13th Mounted Brigade (2/1st Eastern) :

• 2/1st Suffolk Yeomanry Regiment
• 2/1st Norfolk Yeomanry
  Norfolk Yeomanry
  The Norfolk Yeomanry was a regiment of the British Army.In 1901, the Norfolk Yeomanry were raised at the express wish of King Edward VII, after a gap of 33 years, and titled the King's Own Royal Regiment with the Royal cipher as their badge.In September 1915, the regiment embarked on RMS Olympic...
  
   Regiment
• 2/1st Essex Yeomanry
  Essex Yeomanry
  The Essex Yeomanry was a yeomanry regiment of the British Army raised in 1797. The regiment recruited volunteers from the county of Essex in the East of England.-Origins:...
  
   Regiment

14th Mounted Brigade (2/1st South Eastern) :

• 2/1st Royal East Kent Yeomanry
  Royal East Kent Yeomanry
  The Royal East Kent Yeomanry were formed in 1794, originally as a series of independent troops based in the important towns of Kent, England.In the latter part of the 19th century they frequently provided escorts for the Queen and members of the Royal Family, and as a result, in 1856 the East Kent...
  
   Regiment
• 2/1st Queen's Own West Kent Yeomanry
  Queen's Own West Kent Yeomanry
  The Queen's Own West Kent Yeomanry can trace its origins to 1794 when local volunteer troops were raised to assist the civil powers. Each Troop was about 50 strong with three officers , they were required to provide their own uniforms and mounts while the government would supply their arms and...
  
   Regiment
• 2/1st Sussex Yeomanry Regiment

15th Mounted Brigade (2/1st South Western) :

• 2/1st Wiltshire Yeomanry
• 2/1st North Somerset Yeomanry
  North Somerset Yeomanry
  The North Somerset Yeomanry was first raised in Frome in 1798. A condition of service was that it should not be required to march more than 10 miles from the town and it was soon disbanded in 1802...
  
   Regiment
• 2/1st Hampshire Yeomanry
  Hampshire Yeomanry
  The Hampshire Yeomanry can trace its formation to the late 18th century. King George III was on the throne, William Pitt the Younger was Prime Minister of Great Britain, and across the English Channel, Britain was faced by a French nation that had recently guillotined its King and which possessed...
  
   Regiment

16th Mounted Brigade (2/1st Southern) :

• 2/1st Queen's Own Dorset Yeomanry
  Queen's Own Dorset Yeomanry
  The Queen's Own Dorset Yeomanry was founded as the Dorsetshire Regiment of Volunteer Yeomanry Cavalry in 1794. In response to the growing threat of invasion during the Napoleonic wars....
  
  
• 2/1st Hertfordshire Yeomanry
  Hertfordshire Yeomanry
  The Hertfordshire Yeomanry is a British Army unit specializing in artillery and yeomanry that can trace its formation to the late 18th century. First seeing service in the Boer War, it subsequently served in both World Wars....
  
  
• 2/1st Surrey Yeomanry
  Surrey Yeomanry
  The Surrey Yeomanry was a unit of the British Army formed as volunteer cavalry in 1794 during the French Revolutionary Wars. In 1901 the Regiment was granted the title Princess of Wales's which was changed to Queen Mary's when George V became the King...