A nimble survivor during four decades as king of Afghanistan, Mohammad Zahir Shah, who died yesterday at 92, avoided assassination and chaos, both of which often threatened in his backward nation. When he finally was removed in a 1973 coup — by a cousin and former prime minister — he abdicated and retired to Rome, where he watched as Afghanistan slid into oblivion: a countercoup, invasion, and civil war.

When chaos gave way to a perverse stability under the puritanical Taliban, which took power in the mid-1990s, the new rulers banned opium but harbored Osama bin Laden. Accordingly, after September 11, 2001, America toppled the Islamist government and Zahir Shah returned not as king, but with the title of “Father of the Nation.” It was a diminished title for a devastated realm of which the former ruler was, as a Western visitor noted in 2004, “the only remaining archive.”

The last ruler of the Durani dynasty that unified Afghanistan from 1747, Zahir Shah was born October 30, 1914, and educated in France at the Pasteur Institute and the University of Montpellier. He returned home in 1932, at 18, to serve his father as minister of education.

Zahir Shah’s father, Mohammad Nadir Shah, became king in 1929 at the head of a conquering army that deposed and then executed a Tajik, Habibullah Ghazi, whom the Pashtun majority considered a usurper. Nadir Shah was in turn assassinated in 1933 — by some accounts at a school ceremony and by others while leaving his harem — and the 19-year-old Zahir Shah was installed as the new king. The assassin was bayoneted to death.

Zahir Shah ruled an unparalleled four decades, but for the first 30 years he was mostly a figurehead under the thumb of his uncles, who served in the office of prime minister. As was the custom, he married his first cousin.

The year after Zahir Shah was enthroned, Afghanistan joined the League of Nations, the same year its government was officially recognized by America. With a history of being invaded by foreign powers (generally futilely) that went back to Alexander the Great, Afghanistan teetered between West and East and, in the 1930s, tilted somewhat toward Germany.

Afghanistan declared neutrality during World War II and, after the war, managed to extract aid from both camps among the victorious allies: The Soviet Union built the airport in Kabul, while America built the one in Kandahar. Nevertheless, the central government remained weak, the nation was riven by clan loyalties, and cash was often raised by smuggling and raising opium poppies, a trade to which popular reports linked the royal family.

In 1954, the “rule of the uncles” was challenged by a younger generation of the royal family, and Zahir Shah’s cousin and brother-in-law, Mohammad Daoud, was installed as prime minister. In 1964, Zahir Shah oversaw the promulgation Afghanistan’s first written constitution, which provided for a partial democracy and made other reforms. Around that time, Daoud left the government — whether or not it was by choice is disputed. A decade later he would return to unseat the king.

As king, Zahir Shah shone brightest in the 1950s and 1960s, when he met with President Eisenhower, who stopped over in Kabul, and President Kennedy — while taking care also to be photographed with Nikita Khrushchev. A smattering of industry came to Afghanistan and it seemed possible that the nation might modernize. But a drought and famine in the early 1970s proved destabilizing, and in 1973, while the king was taking mud treatments for lumbago on the island of Ischia near Naples, Daoud proclaimed Afghanistan a republic and the monarchy was abolished. (Daoud was killed in another coup five years later.)

Zahir Shah stayed in Rome and abdicated in exchange for a state pension that sustained him through 1979, when it was discontinued after another coup. As Afghanistan changed rule during subsequent decades, Zahir Shah’s return was periodically bruited about as a unifying force. He remained a potent enough symbol that he was stabbed in a 1991 assassination attempt.

When he finally did return in 2002, to open the tribal Loya Jirga that endorsed Hamid Karzai, a fellow Pashtun, as president, it was as a link to a past that must have seemed nearly as remote to ordinary Afghans as the 16th-century glory days of Babur. Zahir Shah had originally come to power the same year that Franklin Roosevelt was sworn in as president.

Afghan society, predictably, remained — and continues — to be as fractious as ever: At Zahir Shah’s death yesterday, a Taliban spokesman called Agence France-Presse to denounce him as a stooge for America.