The British Invasion occurred in the mid-'60s, when a wave of English rock & roll bands crossed over into the American market after the breakthrough success of the Beatles. Though not all of the bands sounded similar -- they ranged from the hard rock of the Rollings Stones and Kinks to the sweet pop of Gerry & the Pacemakers and Herman's Hermits -- each group was heavily influenced by American rock & roll, blues, and R&B. British Invasion bands were either blues-based rockers or pop/rockers with ringing guitars and catchy hooks and melodies. Between 1964 and 1966, the British bands dominated the American charts, as well as the charts in the UK. In that time, there was a second wave of British Invasion bands -- such as the Who and the Zombies -- which were indebted to both American rock and British Invasion pop. By the late '60s, many of the bands had become rock icons but a greater number didn't survive the transition into the post-=Sgt. Pepper= era.
Merseybeat was the original sound of the British Invasion -- a driving, melodic sound that was hybrid of American rock & roll and R&B and British skiffle. The Beatles' early records, like "Please Please Me" and "Love Me Do," were the prototypes of the genre, and soon other Liverpudlian bands like Gerry & the Pacemakers, Billy J. Kramer and the Searchers were following the same style. The sound was called Merseybeat because of the Mersey river in Liverpool. Merseybeat flourished throughout 1963 and the first half of 1964. Shortly afterward, R&B-oriented bands like the Rolling Stones, the Kinks, the Yardbirds appeared, as did pop groups like the Hollies and Freddie & the Dreamers. While these pop groups were influenced by Merseybeat the style itself was losing ground, especially since the Beatles had begun to expand their stylistic reach.