Colonel (U.K.)

Colonel (Col) is a rank of the British Army and Royal Marines, ranking below brigadier, and above lieutenant colonel. British colonels are not usually field commanders; typically they serve as staff officers between field commands at battalion and brigade level. The insignia is two diamond-shaped pips (properly called "Bath Stars") below a crown. The crown has varied in the past with different monarchs; the current Queen's reign has used St Edward's Crown. The rank is equivalent to captain in the Royal Navy and group captain in the Royal Air Force.

The rank of colonel was popularized by the tercios that were employed in the Spanish Army during the 16th and 17th centuries. General Gonzalo Fernández de Córdoba divided his troops in to coronelías (meaning "column of soldiers" from the Latin, columnella or "small column"). These units were led by a coronel. This command structure and its titles were soon adopted as colonello in early modern Italian and in Middle French as coronel.

The rank title entered the English language from French in the mid-16th century and so the modern English pronunciation of the word is derived from the French variant.

The use of the rank of colonel pre-dates the establishment of the United Kingdom. In the mid-17th century, the regiments of the New Model Army were commanded by colonels.

...
Wikipedia