Born in St. Andrews, Fife, the son of a British Army medical officer, Richardson studied classics at Keble College, Oxford.

He served as the Officer in Charge of the British Mission in Lhasa, capital of Tibet, from 1936 to 1940 and again from 1946 to 1950, in the final years having become the diplomatic representative of the recently independent India.

There, in the words of one commentator, "he acted valiantly as a man of honour in a cause which has been largely lost because of the notions of political expediency, where sides are taken without regard to principle and in order not to risk aligning oneself with a potential loser, however deserving he may be" – a position which reportedly earned him the displeasure of both the British and Indian delegations to the UN Assembly.

[8] He remained a close personal friend of the 14th Dalai Lama and of the Tibetan government-in-exile until his death, with the latter describing Richardson as "very precious to us."

Another of Richardson's passions was golf, which he introduced to Tibet, although he noted that the ball tended to travel 'rather too far in the thin air'.