Winston Churchill, widely considered the most celebrated Englishman of the 20th century, is remembered for his political achievements — both his longevity in British politics and as Britain’s indomitable and inspirational wartime leader. First elected to Parliament in 1900 when Victoria reigned as Queen-Empress, he was serving for a second time as prime minister when Victoria’s great-great-granddaughter came to the throne in 1952. Churchill’s finest hour as prime minister occurred during World War II when, as the great conflagration raged, he forged a pivotal partnership with Franklin Roosevelt and marshaled the forces to vanquish the dictators grasping for world dominance.

With his eloquence, ever-present cigar and bulldog visage, Churchill came to personify Britain more than any other political figure has ever done. His political accomplishments now dwarf the acclaim he won as a writer when he received the Nobel Prize in Literature in 1953.

In Mr. Churchill’s Profession, Peter Clarke, a professor of history at Cambridge and a prolific writer of successful books, analyzes how and why Churchill metamorphosed from cavalryman to war correspondent to historian. Churchill’s first foray into print was motivated in part by financial necessity, related to the towering bills for his parents’ hedonist social life in fin de siècle London and his father’s shocking death from syphilis at age 46. But Churchill also acknowledged that getting his name into print would help him make a name for himself and ease his entry into politics.

Politics was the family business. It had been since Sir John Churchill, the victor at Blenheim and a national hero, became the first Duke of Marlborough in 1702. Winston was the grandson of the seventh Duke and the son of Lord Randolph Churchill, who had a meteoric but ultimately failed career in politics. Winston idolized his father, and from his youth he aimed to follow Lord Randolph into Parliament.

Winston’s mother was Jennie Jerome, an American heiress whose marriage to Randolph was marked by the mutual infidelities not uncommon in their social set. As an impecunious widow, still beautiful and willing to use her extensive social network to help her son, she provided him with introductions to prominent people. She was not above acting as his agent to get his war dispatches into the London newspapers. Fortunately for Winston, there were wars aplenty to cover — wars that were spawned by the teeming empire and the unsettled nature of European politics.

Winston’s initial war dispatches became a book, The Story of the Malakand Field Force. The first of several war stories, it included accounts of some of his own heroics, and the book sold well in Britain and the United States. The journalist’s transition to an author became evident with the publication in 1899 of The River War, which began with an insightful explanation of the British policies leading up to the African war. In that book, Peter Clarke writes, we get for the first time Churchill’s voice as an historian, and in it he employs the style and tone that came to characterize his writing.

Capitalizing on the celebrity of his books, but still writing laboriously in longhand, Churchill wrote himself into Parliament by 1900. Lord Randolph Churchill, a biography of his father, was the last book he wrote on his own. After leaving the Tory party to join the Liberals, Churchill started a decade of service in the Cabinet; he began dictating his work to staff members, which enabled him to speed up his writing, polish his phrases and improve his oratorical skills.

Clarke does not allow his obvious recognition of Churchill’s stellar gifts to color the clear-eyed treatment of Churchill as an author. Clarke shows us Churchill’s sybaritic love of luxury, especially the fine brandies and vintage champagnes that became part of the Churchill mystique. The lifelong battle to pay for those luxuries entailed juggling government pay checks, book advances, royalty payments, lecture fees and income from screenwriting, an Irish inheritance and sales of collections of his speeches.

Churchill’s country home in Kent, Chartwell, was his preferred place to write, but it was also a money pit; its management and upkeep challenged his wife, Clementine. Consequently, Churchill faced a Sisyphean struggle for money — often overcommitting himself, missing deadlines and forcing marathon nocturnal dictating sessions with typists working in shifts. Sometimes the quality of his work suffered, sometimes the author leaned too heavily on the ever-changing cast of researchers and scholars he employed. He needed lucrative publishing arrangements, and agents willing to wring the most money from the torrential flow of words from Chartwell, cognizant all the while of his Inland Revenue obligations, especially when he became chancellor of the exchequer.

In Churchill’s “wilderness years,” as he referred to the 1930s when he was out of office, he devoted most of his time to writing. He remained politically visible by producing bimonthly articles on foreign affairs, for which he was handsomely compensated. The first volume of his long overdue biography of Marlborough, his ancestor, appeared during that time. The lengthy gestation of Marlborough: His Life and Times revealed Churchill’s struggle to condense his work — a problem that dogged him as he tackled complex topics.

He was overly optimistic about his ability to meet deadlines, and he found it difficult to condense his manuscripts to a length negotiated with his publishers and acceptable to readers. Nowhere is this more evident than in his book A History of the English-Speaking Peoples. Published in 1956, it took him nearly 25 years to complete, with much of the writing done in 1938-9, on the eve of war. In it, Churchill examined and celebrated the distinctive qualities he perceived to be inherent in English-speaking people: faith in the rule of law, respect for fundamental fairness, pride in history, and courage.

With those thoughts still fresh in mind, the author Winston Churchill stepped away from his writing of the book in 1940 and into No. 10 Downing Street and onto the world stage. Believing fully in the theme of his unfinished book, Churchill looked confidently across the ocean for the lifeline his island nation required. The grand alliance was forged, the war was won, and the author returned to his unfinished book.

Mr. Churchill’s Profession is every bit as good as Hope and Glory: Britain 1900-2000, The Last Thousand Days of the British Empire and Clarke’s lengthy list of excellent histories. Anglophiles especially, but readers of history in particular, will want to seek out this book, find a comfortable chair and wish they were at Chartwell.

Penelope Farthing, an attorney and bibliophile, practices law in Washington, D.C. She is a Hoosier by birth and holds a B.A. from Purdue University and a J.D. from the Mauer School of Law at Indiana University. She lives with her husband and teenage twins in the Georgetown neighborhood.