Patrick Cosgrave, who died in London on September 16th, less than two weeks before his 60th birthday, had an early life of exceptional distinction. He rose from an impoverished background in Dublin to become a star history student in Cambridge, deputy editor of the Spectator at the age of 29 and special adviser to Mrs Thatcher when she was leader of the opposition.
Then, after her victory at the 1979 general election (when it seemed possible that he might even follow in the unique footsteps of Churchill's Irish henchman, Brendan Bracken, into a British government) he fell from favour.
While he continued to produce interesting political writing until the early 1990s he never exercised influence again.
Always an imprudent drinker and an inveterate smoker he was plagued by ill-health and disappeared from public view years before his death.
Patrick Cosgrave was the only child of a widowed mother who had been reduced to poverty by the death of her improvident builder husband when Patrick was only 10.
To make ends meet she worked as cleaner of the Chapel Royal in Dublin Castle. Patrick attended St Vincent's CBS in Glasnevin.
He was a courageous young lad and once played on to the end of a football match despite having a broken toe.
The onset of rheumatic fever at the age of 14 brought his running and football to an end and left him with a weak heart. During the months he spent alone recovering he began to read British history and was dazzled by tales of imperial glory.
He studied history at University College Dublin where he took a first. He became auditor of the Literary and Historical Society. In partnership with Tony (now Professor Anthony) Clare he won The Irish Times Trophy for student debating back in two successive years.
His impassive demeanour and capacity for well-reasoned analytical argument supplemented Clare's more combative style to make an unbeatable team. They also won the Observer Mace in competition with all the universities of these islands outside Oxbridge.
At Peterhouse, Cambridge, he wrote a doctoral thesis on British foreign policy during the first World War.
He had long planned to make his life in England. To emphasise his new persona, he acquired a British passport and, although never really a believer, took to regular attendance at Church of England services.
Yet he was pleased to be head-hunted by RT╔ as their London correspondent. He did splendidly, speaking in the impassive lofty tones of an English insider. This provoked the inevitable Irish begrudgers to throw his poor background (which he never really denied) in his face.
As a political correspondent he made useful contacts. The Conservative Party employed him. He also wrote for the Spectator and they recruited him as political editor in 1971.
Disenchanted with Edward Heath's leadership, he was part of a circle within the party who favoured free market economics and were sceptical of British involvement in Europe. He was one of the first to identify Margaret Thatcher as a prospective leader.
When she succeeded Edward Heath in 1975 he became her political adviser and speechwriter. In 1978 he wrote Margaret Thatcher: a Tory and her party; it was a book more of the genre of propaganda than biography.
But the high life of political journalism led to too much drinking and he was often footless. Even when sober, he was given to flights of fantasy. His account of any situation was as likely to reflect his hopes as the reality.
What exactly occurred to make Mrs Thatcher drop him so completely after she became Prime Minister in 1979 has never been clear.
It was uncharacteristic as she was famously loyal to those who had served her.
If his political dreams were shattered his career as a writer continued to prosper. For a period he was editor-in-chief of Tiny Rowland's group of newspapers.
But his ostrich-like stubbornness and compulsive unreliability made him a difficult subordinate and he had to settle for a more isolated existence as a freelance writer.
The academic impartiality that had won him plaudits when he produced Churchill at war in 1974 deserted him and his later books as well as his journalism was polemical in style and often too partisan in content. His own favourite among his 14 books was The lives of Enoch Powell (1989). He argued that Powell was a harbinger of Thatcherism.
It was his view that Celts, like Powell and presumably himself, had gifts of political foresight denied to native Englishmen.
He loved to provoke.
In the early 1980s and on one of his rare visits to Ireland he outraged viewers of the Late Late Show by suggesting that the army should be given its head in Northern Ireland, the Border closed and the Irish in Britain who did not carry a British passport treated as aliens.
It was perhaps an irony that for all his espousal of English nationalism, he had a poor understanding of the English and in his drinking, talkativeness and general extravagance behaved in the manner many of them would have regarded as rather Irish.
He was reckless in the management of his personal life. He was often more generous than his means allowed and dealt with the demands of the Revenue by ignoring them.
After he had failed to attend several court hearings he was declared bankrupt in 1983.
Two of his marriages, the first to Ruth Dudley Edwards, the writer, ended prematurely.
His third wife, Shirley Ward, whom he married in 1981, cared lovingly for him through years of ill-health that preceded his death.
She recognised in him, as did his friends, a decent, compassionate man possessed of a valiant spirit.
He is also survived by a daughter of his second marriage, which was to Norma Green.
Patrick Cosgrave: born 1941; died, September 2001