English rock group Slade was founded in Walsall in 1966. They became well-known in the early 1970s glam rock era, with 17 straight top 20 successes and six number one hits on the UK Singles Chart. Based on single sales, The British Hit Singles & Albums identifies them as the most successful British group of the 1970s. They became the first group to debut three singles at the top of the charts. Writers Jim Lea and Noddy Holder wrote the lyrics for all six of the band's hit songs. With over a million copies sold of their best-selling single, "Merry Xmas Everybody," their total UK sales as of 2006 stand at 6,520,171. The 1999 BBC documentary It's Slade claims that the band has sold more than 50 million records globally.