Almost 43 years ago, on April 3, 1973, Martin Cooper from Motorola made the first call on a mobile phone. It was a business call to a rival manufacturer, also in the race to develop a portable, hand-held device.
That phone weighed about a kilogram; its brick-like heavy battery took 10 hours to charge and allowed a talk time of only 30 minutes. Hardly what you might call mobile. But it was a start.
Development of the mobile phone continued, and a decade later they were on sale in the USA for the equivalent of £2,500 each.