Glengarry The glengarry bonnet is a traditional Scots cap made of thick - milled wool len material , decorated with a toorie on top , frequently a rosette cockade on the left side , and with ribbons hanging down behind . It is normally worn as part of Scottish military or civilian Highland dress , either formal or informal , as an alternative to the Balmoral bonnet or tam o ' shanter . The Royal Regiment of Scotland wears the glengarry with diced band and black cock feathers as its ceremonial headdress . History . Traditionally , the ' glengarry bonnet ' is said to have first appeared as the head dress of the Glengarry Fencibles when they were formed in 1794 by Alexander Ranaldson MacDonell of Glengarry , of Clan MacDonnell of Glengarry . MacDonnell , therefore , is sometimes said to have invented the glengarry but it is not clear whether early pictures of civilians or fencible infantry show a true glengarry , capable of being folded flat , or the standard military bonnet of the period merely ' cocked ' into a more ' fore - and - aft ' shape . The first use of the classic , military glengarry may not have been until 1841 , when it is said to have been introduced for the pipers of the 79th Foot by the commanding officer , Lieutenant Colonel Lauderdale Maule . It was only in the 1850s that the glengarry became characteristic undress headgear of the Scottish regiments of the British Army . By 1860 , the glengarry without a diced border and usually with a feather had been adopted by pipers in all regiments except the 42nd ( Black Watch ) , whose pipers wore the Full Dress feather bonnet . In 1914 , all Scottish infantry regiments were wearing dark blue glengarries in non - ceremonial orders of dress , except for the Cameronians ( Scottish Rifles ) who wore them in rifle green , and the Scots Guards , who wore peaked forage caps or khaki service dress caps . The diced bands on glengarries were either in red , white and blue for Royal regiments or red , white and green for others . The toories on top could be red , royal blue or black , according to regiment . The Black Watch and Queen ' s Own Cameron Highlanders , however , wore glengarries without dicing and The 93rd ( Sutherland ) Highlanders were unique in wearing a simple red and white chequer pattern . This was said to commemorate the stand of the 93rd Sutherland Highlanders at the Battle of Balaclava immortalized as The Thin Red Line . Between 1868 and 1897 , the glengarry was also worn as an undress cap for most British soldiers until replaced by the short - lived Field Service Cap . When this was revived in 1937 , the " Dress Regulations for the Army , " described the Universal Pattern Field Service Cap ( used by the British Army in World War II ) as " similar in shape to the Glengarry . " Modern wear . The glengarry continued to be worn in dark blue by all regiments of the Scottish Division up to their final amalgamation into the Royal Regiment of Scotland in 2006 . In parade dress , it was worn by all regiments except the Black Watch , who wore the blue balmoral bonnet , and musicians of some regiments , who wore feather bonnets in full dress . The Cameronians ( Scottish Rifles ) wore a plain rifle green glengarry up until their disbandment in 1968 . The blue glengarry currently worn by the Royal Regiment of Scotland has red , blue and white dicing , a red toorie , black silk cockade and the regimental cap badge surmounted by a cock feather . This last is a tradition taken from the Royal Scots and King ' s Own Scottish Borderers . Other Commonwealth military forces that have Scottish and Highland regiments also make use of the glengarry . Scottish companies and pipe bands of the Australian Army also wear the glengarry . Irish Army . The headdress worn by Irish Army pipers is called a Glengarry but is more similar to the caubeen in appearance , than to the Scottish headdress of the same name . It was designed in 1934 for the Cavalry Corps as a more practical headdress than the standard peaked cap in the confines of their armoured cars and tanks . The Glengarry is the same colour as the army ' s service dress uniform with a black band and two black swallow - tail ribbons at the rear . The cap badge is worn over the left eye . Officers in the RDF wear a similar Glengarry but with green band and ribbons as part of their service dress uniform . Army pipers and drummers wear a black Glengarry with a saffron band and ribbons and a dark green feather hackle . Civilian wear . The glengarry is worn by male members of staff at the Palace of Holyroodhouse , the Queen ' s Official residence in Scotland . The glengarry is also commonly worn by civilians , notably civilian pipe bands , but can be considered an appropriate hat worn by any man with Highland casual dress or day wear . In this context , it most often has a red toorie . In pipe bands , women often also wear the glengarry . The Glengarry is the headress stipulated in Dress Regulations for Officers of the Boys ' Brigade ; namely Warrant Officers , Lieutenants and Brevet Captains . Police use of diced band . In 1932 Percy Sillitoe , the Chief Constable of the City of Glasgow Police , abolished the traditional custodian helmet and added a new feature to the peaked cap s worn by his police officers . This new feature was a black and white chequered cap band based on the dicings seen on the glengarry headress of the Scottish regiments . The diced band , popularly known as the Sillitoe Tartan , later spread to police forces in Australia , New Zealand , and the rest of the United Kingdom , as well as to some other parts of the world , notably Chicago . Method of wearing . The correct method of wearing the glengarry has changed since the end of WWII . Prior to 1945 , glengarries were generally worn steeply angled , with the right side of the cap worn low , often touching the ear , and the side with the capbadge higher on the head . The trend since the end of the war has been to wear the glengarry level on the head .