regiments, the Mercian Regiment, founded in 2007, which recruits in Cheshire, Derbyshire, Nottinghamshire, Worcestershire, and parts of Greater Manchester and the West Midlands, and the Royal Mercian and Lancastrian Yeomanry, founded in 1992 as part of the Territorial Army. In 1967, the police forces of Herefordshire, Shropshire and Worcestershire were combined into the West Mercia Constabulary, which changed its name to West Mercia Police in 2009. Telephone directories across the Midlands include a large number of commercial and voluntary organisations using "Mercia" in their names, and in 2012 a new football league was formed called the Mercian Regional Football League. Free Radio Coventry & Warwickshire, a commercial radio station, was originally launched in 1980 as Mercia Sound, later becoming Mercia FM. Symbolism and attributed heraldry There is no authentic indigenous Mercian heraldic device, as heraldry did not develop in any recognizable form until the High Middle Ages. The saltire as a symbol of Mercia may have been in use since the time of King Offa. By the 13th century, the saltire had become the attributed arms of the Kingdom of Mercia. The arms are blazoned Azure, a saltire Or, meaning a gold (or yellow) saltire on a blue field. The arms were subsequently used by the Abbey of St Albans, founded by King Offa of Mercia. With the dissolution of the Abbey and the incorporation of the borough of St Albans the device was used on the town's corporate seal and was officially recorded as the arms of the town at an heraldic visitation in 1634. The saltire is used as both a flag and a coat of arms. As a flag, it is flown from Tamworth Castle, the ancient seat of the Mercian Kings, to this day. The flag also appears on street signs welcoming people to Tamworth, the "ancient capital of Mercia". It was also flown outside Birmingham Council House during 2009 while the Staffordshire Hoard was on display in the city before being taken to the British Museum in London. The cross has been incorporated into a number of coats of arms of Mercian towns, including Tamworth, Leek and Blaby. It was recognised as the Mercian flag by the Flag Institute in 2014. The silver double-headed eagle surmounted by a golden three-pronged Saxon crown has been used by several units of the British Army as a heraldic device for Mercia since 1958, including the Mercian Regiment. It