A bayonet is a short sword/knife that soldiers would attach with a locking mechanism to the front of their rifles during battle making the bayonet a deadly weapon in close hand to hand combat with the enemy when there is not enough time to reload a gun with bullets or when ammunition has been depleted.
Bayonet charges of the enemy position had been a standard military tactic in the British army and WWI saw this tactic once again employed in charging the German trenches en mass. Every soldier was provided with their own bayonet which was carried in a holster attached to their belt and easily accessible when needed. Although designs have changed over the years, the bayonet continue to be used by most armies around the world which is remarkable given that it was first used by armies in the 17th century.
Thakur Singh's bayonet is a WWI era British Lee Enfield SMLE Pattern 1907 Bayonet designed to fit the Short Magazine Lee-Enfield No 1, Mk III infantry rifle.
Blade Length: 17.00 in
Overall Length including handle: 21.75 in
Markings on the bayonet indicate that the bayonet was manufactured at the Royal Small Arms Factory in Enfield England in November 1914 and issued to a British Indian Army unit. 
British Indian Army Markings on Pommel in Urdu – 1321
Marks on blade side 1
Crown/G.R. – Georgius Rex (King George V)
1907 – Pattern 1907
11 ’14 – Manufacture date, November 1914
EFD – Manufacturer: Royal Small Arms Factory, Enfield
Marks on blade side 2
Broad arrow – Government acceptance mark
Crown/35/E – Enfield inspection mark
LF/16 – secondary inspection mark
X – bending test proof marks
1. Bryan Brown, Markings on British and Commonwealth Bayonets, http://www.radix.net/~bbrown/brit_bayo.html (2003)