Born and raised in the Southern Rhodesian capital Salisbury, Beadle read law in the Union of South Africa and in Great Britain before commencing practice in Bulawayo in 1931.

Appointed Huggins's Parliamentary Private Secretary in 1940, he retained that role until 1946, when he became Minister of Internal Affairs and Justice; the Education and Health portfolios were added two years later.

In 1961, he was knighted and appointed Chief Justice of Southern Rhodesia; three years later he became president of the High Court's new Appellate Division and a member of the British Privy Council.

Beadle held the Rhodesian Front, the governing party from 1962, in low regard, dismissing its Justice Minister Desmond Lardner-Burke as a "small time country solicitor".

[2] The family was politically conservative and favoured joining the Union of South Africa during the latter years of Company rule, sharing a firm consensus that Sir Charles Coghlan and his responsible government movement were, in Beadle's recollection, "a pretty wild bunch of jingoes".

The criteria were applied equally to all regardless of race, but since most black citizens did not meet the set standards, the electoral roll and the colonial Legislative Assembly were overwhelmingly from the white minority (about 5% of the population).

He formed a good relationship with Aneurin Bevan, the UK Minister of Health, and put considerable work into attempting to create a Southern Rhodesian system similar to National Insurance in Britain.

[8] This decision surprised many of his contemporaries; Beadle would explain later that he left politics as he did not feel he would work well under his United Party colleague Edgar Whitehead, whose subsequent rise to the premiership he correctly predicted.

[n 1] Beadle argued that since the British government would never devolve indigenous African affairs to Federal responsibility, native policy in the three territories would never be co-ordinated, meaning "the thing was bound to crash".

RF proponents downplayed black nationalist grievances regarding land ownership and segregation, and argued that despite the racial imbalance in domestic politics—whites made up 5% of the population, but over 90% of registered voters—the electoral system was not racist as the franchise was based on financial and educational qualifications rather than ethnicity.

[36] In this latter role, he blocked a Legislative Assembly act to extend periods of preventive restriction outside times of emergency, ruling it against the declaration of rights contained in Southern Rhodesia's 1961 constitution.

The British High Commissioner in Salisbury, J B Johnston, had few doubts about how Beadle would respond to such an act, writing that he was "quite certain that no personal considerations would deflect him for a moment from administering the law with absolute integrity.

"[37] Arthur Bottomley, the British Сommonwealth Secretary, took a similar line, describing Beadle to the Prime Minister Harold Wilson as "a staunch constitutionalist" who would be disposed to "frustrate any illegal action by Mr Smith's government".

[39] Wilson told the British House of Commons that Beadle had provided "wise advice" to both governments, and was "welcome [in] this country not only for his sagacity, judgement, and humanity but as a man with the courage of a lion.

[39] Before announcing UDI to the nation, Smith, Lardner-Burke and the Deputy Prime Minister Clifford Dupont visited Gibbs at Government House to inform him personally and ask him to resign.

[44] Beadle summarised the Rhodesian judiciary's position in light of UDI by saying simply that the judges would carry on with their duties "according to the law",[45] but this non-committal stance was challenged by legal cases heard at the High Court.

[51] On 5 December 1966, when Beadle heard at Government House that Smith's ministers had rejected the terms, he stood "as though pole-axed", Gibbs's Private Secretary Sir John Pestell recalled, and appeared close to collapse.

Erwin Griswold, the United States Solicitor General, wrote to him that as he saw it the Rhodesian judges could not recognise the post-UDI government as de facto while also claiming to act under the Queen's commission.

[46] Sir Robert Tredgold, the former Southern Rhodesian and Federal Chief Justice, told Gibbs that Beadle had thereby "sold the pass" and "should be asked to leave Government House".

[43] The following month, considering the fate of James Dhlamini, Victor Mlambo and Duly Shadreck, three black Rhodesians sentenced to death before UDI for murder and terrorist offences, Beadle upheld Salisbury's power to execute the men.

[52] At the hearing for Dhlamini and Mlambo on 4 March 1968, Beadle dismissed the statement from London, saying it was a decision by the UK government and not the Queen herself, and that in any case the 1961 constitution had transferred the prerogative of mercy from Britain to the Rhodesian Executive Council.

[37][n 3] In his analysis of Beadle's behaviour, Manuele Facchini suggests that the Chief Justice considered the matter from a dominion-style viewpoint — by stressing the 1961 constitution and the rights held by Salisbury thereunder, he was repudiating not the royal prerogative itself, but rather the attempt to exercise it at the behest of British rather than Rhodesian ministers.

[54] Kenneth Young comments that the British government's involvement of the Queen inadvertently strengthened the post-UDI authorities' position; outraged, many in Rhodesia who had heretofore rejected UDI now threw their weight behind the RF.

[59] Beadle and his judges granted full de jure recognition to the post-UDI government on 13 September 1968, while rejecting the appeals of 32 black nationalists who one month earlier had been convicted of terrorist offences and sentenced to death.

[46] The British Commonwealth Secretary George Thomson expressed outrage, accusing Beadle and the other judges of breaching "the fundamental laws of the land",[60] while Gibbs stated that since his position as governor existed under the 1961 constitution he could only reject the ruling.

The British Prime Minister minimised the political impact of the Chief Justice's decision by presenting it as evidence that Beadle had furtively supported UDI all along, and subsequently excluded him from the diplomatic dialogue.

[65] Michael Stewart, Wilson's Foreign Secretary, recommended that Britain take preliminary steps towards removing Beadle from the Privy Council if the Chief Justice did not resign or dissociate himself from the republic "within a week or two" after the new constitution came into force.

Given the gravity of such an action—only one privy counsellor, Sir Edgar Speyer, was struck off the list during the 20th century — and the likelihood that accusations of vindictiveness would result, the British government was loath to do this, and hoped that Beadle would remove the need for it by resigning.

[66] In May 1973, Beadle chaired the High Court appeal hearing for Peter Niesewand, a freelance reporter for the overseas press who had been convicted of espionage under the Official Secrets Act, prompting outcry abroad.

[73] Beadle continued to serve under the short-lived, unrecognised government of Zimbabwe Rhodesia, which replaced the Rhodesian republic in June 1979, and under the British interim authorities following the Lancaster House Agreement of December that year.