Sir Curtis Keeble was Ambassador to the Soviet Union for four difficult years between 1978 and 1982. He went to Moscow at the end of a long Diplomatic Service career, distinguished in particular by his work as Britain’s first ambassador to East Germany and then in London as the deputy under-Secretary of state responsible for the service’s administration. Yet he did not look or sound the part that he played so well. His face was homely, he took pride in his simple origins, his voice rose frequently to the falsetto. He was an odd figure in the regalia of the GCMG with which his services were marked when he retired in 1982.

Herbert Ben Curtis Keeble was born in 1922 and educated at Clacton County High School. His father was the borough clerk for Bethnal Green Council in East London. Keeble went to London University but his education was interrupted by army service in the Second World War and he spent five years in uniform. As a result he never obtained a degree. It was during his wartime service that he learnt to speak fluent Russian and met his wife, Margaret Fraser, who was also serving in the Army.

Entering the Foreign Service in 1947 he embarked on the usual succession of postings in London and overseas. From what looked like and probably were haphazard appointments in his early and middle years two themes emerged. Postings in Berlin and Berne strengthened his German; and repeated employment on economic and commercial work gave him what was in those years a still rare authority in these fields.

But Keeble’s first opportunity to shine came in 1974, when at the age of 52, he was appointed Ambassador to East Germany. Relations had been established a year earlier, after nearly 30 years of international ostracism of the German Democratic Republic and a long game of grandmother’s footsteps about diplomatic recognition of the old pariah. But difficult issues remained: the responsibilities of the four wartime Allies for Germany as a whole; divided Berlin; the priority of the Federal Republic for British interests; and the unpalatable nature of the East German regime. To these political difficulties were added the problems of establishing a new mission. Keeble took all of them in his stride.

His reward was to be posted back to London as Chief Clerk in 1976. The job, which sounds so humble, was one of the most important and sensitive in the Foreign and Commonwealth Office, carrying as it does responsibility for all administrative matters: finance, personnel, security and accommodation for a service scattered all over the world, much of it in penny packets.

Keeble came to it at a particularly difficult juncture. In the autumn of 1976 the IMF came to London, demanding retrenchment that affected all areas of public expenditure. The financial squeeze on overseas representation intensified. At the same time the press was voicing widespread dissatisfaction with a style of diplomacy thought inappropriate to the nation’s straitened circumstances. A group of think-tank Young Turks produced recommendations for change which others saw as crassly destructive of a service of quality. A young and arrogant Foreign Secretary got at cross purposes with old and crusty diplomats. In 1977 he appointed a 40-year-old outsider to the service’s greatest prize, the embassy in Washington. On all sides Keeble faced dissatisfaction and suspicion. Doggedly, practically, he did what had to be done and held the service together through three difficult years.

In 1978 he was promoted to the Moscow embassy. It was a black time for East-West relations. Hopes of détente, so live in the earlier Seventies, were fading fast. The Soviet leadership seemed intent on piling up arms in Europe, developing a global reach, and testing Western will around the world. Moscow saw Britain, after the United States, as its principal opponent, a conviction reinforced when Margaret Thatcher assumed office a year after Keeble’s mission began. At the same time, the invasion of Afghanistan and fears of a Soviet threat to the Gulf increased tensions. So did the missile deployment poker game — cruise and Pershing versus SS20 — which was still developing when the time came for Keeble to leave Moscow on retirement in 1982.

Despite the dire state of East-West relations, Keeble in his quiet way established warm personal relations with the Russians with whom he had to deal and formed a close friendship with the Soviet Foreign Minister, Andrei Gromyko. As a farewell Keeble and his family were given a special tour of the secret part of the Kremlin rarely ever seen by foreigners.

Throughout his service in Moscow Keeble demonstrated that he was the right man for the times. He did not care for easy popularity; he was wary of the intellectual fertility which can so easily weaken the diplomatic hand when times are bad; and he had the toughness to trade argument for unpalatable argument with the Kremlin. At the same time he had an eye for trade opportunities, few as they were. He brought no triumphs home from Moscow, but he retired with a reputation for having played a difficult hand well to the very end.

Foreign affairs continued to preoccupy him. He served briefly as adviser to the House of Commons Foreign Affairs Committee, much longer as chairman of the GB-USSR Association and on the councils of Chatham House and the London School of Slavonic and East European Studies. Keeble was also a governor of the BBC from 1985 to 1990. He also contributed to books on the Soviet system and was still hard at work when the miracles of change began. But he remained without pretension: a man for the back row at public meetings and the train home to Thames Ditton at the end of the day.

Keeble had a passionate interest in Russian culture and also throughout his life was a keen sailor, often sailing off the East Coast. His ancestors were all seafarers and originally bargemen from Essex who went on to crew tea clippers. His grandfather settled in the East End of London running barges up and down the Thames.

Until his last few years Keeble and his wife would sail out into the North Sea from Walton-on-the-Naze on board their small sailing boat Kukla, the name of a Russian doll.

Keeble is survived by his wife, Margaret, and their two daughters: Suzanne, a medical doctor, and Sally, the Labour MP for Northampton North. A third daughter pre-deceased him.

Sir Curtis Keeble, GCMG, diplomat, was born on September 18, 1922. He died on December 6, 2008, aged 86