Today, the Lord-Lieutenant is largely an honorary position, usually awarded to a retired notable person in the county.
Lieutenants were first appointed to a number of English counties by King Henry VIII in the 1540s, when the military functions of the sheriff were handed over to him. He raised and was responsible for the efficiency of the local militia units of the county, and afterwards of the yeomanry, and volunteers. He was commander of these forces, whose officers he appointed. These commissions were originally of temporary duration, and only when the situation required the local militia to be specially supervised and well prepared; often where invasion by Scotland or France might be expected.
Lieutenancies soon became more organised, probably in the reign of his successor King Edward VI, their establishment being approved by the English parliament in 1550. However, it was not until the threat of invasion by the forces of Spain in 1585 that lieutenants were appointed to all counties and counties corporate and became in effect permanent. Although some counties were left without lieutenants during the 1590s, following the defeat of the Spanish Armada, the office continued to exist, and was retained by King James I even after the end of the Anglo-Spanish War.
he King's most Excellent Majesty, his Heirs and Successors, shall and may from Time to Time, as Occasion shall require, issue forth several Commissions of Lieutenancy to such Persons as his Majesty, his Heirs and Successors, shall think fit to be his Majesty's Lieutenants for the several and respective Counties, Cities and Places of England and Dominion of Wales, and Town of Berwick upon Tweed.