Number 9...Number 9...Number 9...

No, this isn't a refrain from one of the Beatles' Top 10 hits.

But it does boast British ancestry.

It's the name of a British knife bayonet, circa the mid-1900s.

Bayonets have been associated with specific guns that carried them into battle. In this case, we have the No. 5, No. 7 and No. 9 bayonet series that are inexorably linked-attached at the muzzle, as it were, to the Pride of Britannia-the immortal STEN Gun and the Enfield infantry rifle, No. 4, Mark 1.

What action movie fan hasn't watched spellbound as brave English commandos streak across an unnamed German bridge-Hitler's backdoor, into a hail of fire-Sten guns blazing, bagpipes blaring?

The STEN gun got its name from an abbreviation of Major Reginald Shepherd and Harold Turpin. The EN is short for Enfield Arsenal. Quite nice of those chaps to include every blooming person or thing associated with this handy little WWII submachine gun (SMG) chambered in 9x19 mm.

Sten guns were produced from the outset of the war-1941 through 1960. Military and paramilitary forces throughout the U.K. , Scandinavia and Europe were issued the Sten, and this ubiquitous SMG saw action in numerous wars and conflicts (and Hollywood movies) to include World War II, the Korean War, the Mau Mau Uprising and the 1948 Arab-Israeli War.

About four million units were made at the Royal Small Arms factory in Enfield.

This blowback, fully auto SMG shoots from an open bolt and has a rate of fire between 450 and 600 rounds per minute by way of its 32-round magazine. Effective range is 50 to 200 meters.

The Sten Mark V was made in 1944 and came with a wooden stock, pistol grip, and bayonet. Yup, an SMG with a pig sticker, and the Sten Mark VI could be silenced-awesome.

What TV movie fan hasn't watched British infantry fight Hitler or Tojo's boys, their Enfield rifles blazing, bayonets fixed, ready to spring out of foxholes and engage in hand-to-hand combat?

The British bayonets in question, the No. 5, No. 7 and No. 9 knife-bayonet fitted such guns.

The No. 5 bayonet fit the Rifle No. 5, Mark 1 Jungle Carbine. It's 7.9 inches long, single-edged and has wood grips and a large muzzle ring that fits nicely over the Jungle Carbine's flash suppressor.

The No. 7 bayonet was made for the Rifle No. 4, Mark 1 Enfield in .303. Some No. 7 bayonets are converted No. 5's. The bayonet ring was fitted over the muzzle of the No. 4, Mk1, and a pivoting socket locked it securely to this British infantry rifle. The No. 9 is an 8-inch socket bayonet sans handle, with a long fuller and a Bowie-knife blade that also fitted the No. 4, Mk1 rifle.

Jolly good show, what?