The Sinclair Sovereign was a high-end calculator introduced by Clive Sinclair's company Sinclair Radionics in 1976. It was an attempt to escape from the unprofitable low end of the market, and one of the last calculators Sinclair produced. Made with a case of pressed steel that a variety of finishes, it cost between and at a time when other calculators could be purchased for under . A number of factors meant that the Sovereign was not a commercial success, including the cost, high import levies on components, competition from cheaper calculators manufactured abroad, and the development of more power-efficient designs using liquid-crystal displays. Though it came with a five-year guarantee, issues such as short battery life limited its usefulness. The company moved on to producing computers soon afterwards. The design by John Pemberton won a Design Council award, and there are examples of the Sovereign in the Museum of Modern Art in New York. It had a Mostek MK50321N main integrated circuit and a small memory register, a LED display, and could perform a variety of a number of basic mathematical operations besides four-function arithmetic. History The Sovereign was one of the last calculators produced during Sinclair's foray into the calculator market that had started with the Sinclair Executive in September 1972. The Executive had retailed for when introduced, but in little over a year it was possible to purchase a Sinclair calculator for and by November 1976 a model was available for . Cheaper calculators with liquid-crystal displays instead of light-emitting diodes were becoming more popular, and had much longer battery lives of months or years. Such calculators were available for well under , with all the functionality of the more expensive models. The impossibility of selling "simple" calculators profitably led Sinclair to introduce models such as the Cambridge Scientific, introduced in August 1975 at a price of . The Sovereign, released in 1976, represented an attempt to move upmarket in an increasingly saturated market. In December 1976, the chrome plated version of the Sovereign cost and the gold-plated version , including VAT, but profit margins on the Sovereign were so small that Sinclair ended up selling the Sovereign at a loss, and it was not a commercial success. The Sovereign was made in England, like every other Sinclair calculator except the President. Sinclair would shortly stop producing calculators and instead focus on computers, starting with the MK14 in