Now this is a very interesting set, but oddly it does not seem to say anywhere that the colours used as a background to the badge are actually the same colours as on their Regimental Neck Tie. The giveaway for me was the card of the Royal Artillery, whose zig zag red and black pattern is immediately recognisable.
Our card is of the Middlesex Regiment, which is an amalgam of several earlier ones. Originally it was formed from the 57th, or West Middlesex Regiment, and the 77th, or East Middlesex Regiment. This happened in 1881, after which the name became The Middlesex Regiment (Duke of Cambridge's Own).
This name remained until 1966, when it became part of an even larger conjoining under the title of The Queen`s Regiment. Most of these Regiments were from places in London and the Home Counties, but also including Sussex.
After such upheaval, it seems sad that it only endured this title for a few years, before being changed again to The Princess of Wales` Royal Regiment, and now encompassing the Royal Hampshires.
We need to return way further back for the origin of Middlesex Day though, to the time when the West Middlesex Regiment was fighting the Peninsula War, led by the Duke of Wellington. The Regiment was trying to keep the French from invading Portugal when their commanding officer came under fire and lost his horse. Instead of panicking, he yelled out, as loud as he could, "Die Hard, men Die Hard". This was the spur that changed the course of the Battle and the French were repelled. This action not only added the "Albuhera" to their banner (as you can see on many silks) but "The Die-Hards" became the Regimental nickname.
And the date of the Battle of Albuhera was the 16th of May 1811.
Oddly card number 1 of John Player "Badges and Flags of the British Regiments gives the nickname, but below the round belted cartouche at the top it has 77, which was the East Middlesex number and not the West. But the 57th Regiment was definitely the one at Albuhera. So did John Player not go back far enough to find out that the current Middlesex Regiment was once two?