The United Kingdom is an island nation. The sea has always been a vital factor in its history. It has been a means of people arriving from overseas, a barrier to invaders, a highway for trade and the basis for a once global empire. The earliest naval battle we know about in British waters was in 719 between factions of the Dalriata. It is likely there were many similar actions all around these islands from the earliest times. By 1945 the Royal Navy had grown to almost 900 major warships and a force of 866,000 men and women. The post Second World War Royal Navy has seen a transformation as great as that which occurred in the last hundred years. The Navy has had to develop and progress to be ever prepared to defend the British waters from rival forces.