Unhappy at the lack of opportunities for black people in Trinidad, he decided to pursue a career as a professional cricketer in England, and during the 1928 tour was awarded a contract with the Lancashire League club Nelson.

He played for the school cricket team, which he captained in his last two years,[14] by which time he was developing a reputation as an attacking batsman, a good fast-medium bowler and an excellent fielder.

[15] His father prohibited him from playing competitive club cricket until 1920 for fear of premature exposure to top-class opposition while too young; in addition, he first wanted his son to establish a professional career.

[23] An innings for Shannon in 1921 against renowned fast bowler George John received great local publicity,[23][24] but according to the cricket writer and social historian C. L. R. James, this was the only time prior to 1928 that Constantine played in such an effective way.

The white captain of the team, Major Bertie Harragin, recognised the younger Constantine's promise, and selected him to play in Trinidad and Tobago's Inter-Colonial Tournament match against British Guiana.

[note 2] Although in two games he scored only 45 runs and took four wickets,[30] commentators considered his fielding in the covers to be exceptional, and he retained his place in the team largely as a fielder.

[31] Mainly on the strength of his fielding,[32] Austin secured Constantine's selection for the 1923 West Indian tour of England; it was a surprising choice, as there were other candidates who appeared to have stronger claims.

[38] Pelham Warner, a former England captain and influential journalist and administrator, described Constantine after the tour as the best fielder in the world; his fielding was also praised by the press and in the pages of Wisden.

"[24] John Arlott later commented that, on his first tour of England, Constantine "learnt much that he never forgot, by no means all of it about cricket: and he recognised the game as his only possible ladder to the kind of life he wanted.

[47] Constantine realised that to succeed as a professional cricketer, he needed to improve; his bowling lacked true speed and, when batting, he was often dismissed playing shots that were too adventurous.

[85] During the previous winter, England had played Australia in the controversial Bodyline series in which the English bowlers were accused of bowling the ball on the line of leg stump.

[89] Frustrated by a slow pitch which he believed was intended to neutralise his fast bowlers, Grant had ordered Constantine to bowl Bodyline against Yorkshire, and decided to repeat the tactics in the second Test.

Wisden commented: "Constantine, in the mood suggesting his work in Saturday afternoon League cricket, brought a welcome air of gaiety to the Test arena.

By setting himself to master the variety of pitch conditions he encountered, and adopting a style of fast-scoring and occasionally unorthodox batting, he became an adaptable and effective batsman in all forms of cricket, improvising where necessary to prevent bowlers getting on top.

[137] As a cover-point fielder Constantine was, according to Manley, "athletic, panther-quick, sure handed and with an arm that could rifle the ball into the wicket-keeper's gloves like a bullet even from the deepest boundary".

[142] Although Constantine's Test bowling record was modest, this may to some extent reflect the poor standard of fielding in the early West Indies teams, in particular their propensity to drop catches.

"[134] During his time in Nelson, Constantine made a deep impression[144] and remained a celebrity there even after leaving the town;[131] his general community involvement was such that a regional historian described him as a "local champion".

[155] During the war, Constantine continued his cricket career as a league professional;[note 3][156] also, as a popular player who could boost crowd attendances, he appeared in many wartime charity games.

[169] In August 1943 Constantine played in a charity cricket match at Lord's and had booked rooms for himself, his wife and daughter at the Imperial Hotel, London for four nights.

[170] When Arnold Watson, a colleague of Constantine at the Ministry of Labour, arrived and attempted to intervene, he was told by the manager: "We are not going to have these niggers in our hotel,"[171] and that his presence might offend American guests.

[171] The Imperial Hotel incident affected Constantine deeply, both because of the involvement of his family and also because he was due to play cricket for a team representing the British Empire and Commonwealth.

[193] At the time, according to Peter Mason, this was "an explosive, challenging, hard hitting tome, the more so because it came not from a known black militant but from someone who seemed so charming, so unruffled, so suited to British society".

[199] Feeling that the PNM's policies were in harmony with his views on improving the lives of black people, and encouraged by his wife, Constantine stood for election in the parliamentary constituency of Tunapuna in 1956.

[205] According to Mason, the speech was a miscalculation which made the public, perhaps already sceptical of his commitment to Trinidad and Tobago after so many years away, question his fitness for a ministerial role,[204] a view increasingly held by commentators.

[218] Although as High Commissioner Constantine looked after his staff and was respected by other diplomats,[219] Howat observes there is limited evidence that he was successful in the post: "In the one area in which he acted positively, he blundered—the Bristol affair.

[223] In this role he spoke out against the Commonwealth Immigrants Act, a stance that led to an offer from the Liberal Party, which he declined, to stand as parliamentary candidate for the Nelson and Colne constituency.

[229] Constantine was awarded a life peerage in 1969 New Year Honours List, becoming the first black man to sit in the House of Lords; there were rumours that Trinidad and Tobago had prevented earlier attempts to ennoble him.

[237] John Arlott describes Constantine as a man of "easy humour and essential patience ... His outlook was that of a compassionate radical and he maintained his high moral standards unswervingly.

"[40] E. W. Swanton writes: "None could call Lord Constantine a modest man, but gifts of warmth and friendliness as well as a shrewd brain and a ready tongue helped to make him one of the personalities of his time.

"[134] Gerald Howat wrote: "Cricket apart ... Constantine's reputation must rest on his contribution to racial tolerance, his benevolent view of empire and Commonwealth, and his personal acceptance within the British 'establishment'.