This sword, dating from 1805-09, would have been carried by an Inspecteur aux (or 'des') Revues (the equivalent of Commissary in the British Army), responsible for pay, provisions (hence the ears of wheat on the guard and knuckle bow) and the depot system. Before this, they simply carried an ordinary infantry sword. The sword is rare.

Regarding the regiment, the Grenadiers had a very specific gorget with multiple pierce work on both wings, the Scots Guards normally had '3rd Guards' engraved on both sides at the tips, therefore, by elimination, this is almost certainly a Coldstream Guards example. The Dighton watercolours of the period appear to confirm this.

This is an Austrian pattern, which was adopted by the British army in 1796 as a dress sword for Heavy Cavalry general officers and militia units. It would have been used throughout the Peninsula War and at Waterloo and beyond until about 1820 or so.

This is likely to have been made towards the end of the American Revolutionary War (Peace of Paris, 1783) or during the early part of the Napoleonic Wars (starting 1793). This would have been carried by an RN officer or HEIC naval officer, and this example is interesting in having a particularly long (approx 26") blade.

The hilt could be Dutch or French, the use of tortoiseshell having been introduced to Europe in the late 17th century, probably through Dutch colonial connections. The mid 18th-century German blade (26" long) would have replaced an earlier, shorter, straight, double-edged blade (broken?), probably to enable the weapon's use as a naval hanger.