In 1946 - the year Bhumibol Adulyadej became king of Thailand - the second world war had just ended, the first computer was still a work in progress and people were queuing outside cinemas to see Olivia de Havilland in To Each His Own. Thaksin Shinawatra - the outgoing prime minister who met the king this week at the height of Thailand's political crisis - wasn't even born. It remains unclear whether the king intervened as Mr Thaksin announced plans to step aside once parliament opens. Democrats led by Abhisit Vejjajiva boycotted last Sunday's election but now face being shut out of a parliament dominated by Thai Rak Thai, the party Mr Thaksin still heads. In the tense weeks ahead, the king's immense moral authority will be the one constant riding above Thailand's tumultuous political development, as it has for decades. On June 9, it will be 60 years since King Bhumibol ascended to the throne - he is the longest-serving constitutional monarch in modern history, and almost certainly the most revered. The celebrations are expected to be one of the biggest gatherings of international royalty in years. His nation has changed almost beyond recognition in that time, enduring booms and busts on the way to becoming a commercialised, developing nation. Thailand found itself at the epicentre of the cold war for much of that time as Indochina became engulfed in conflict and the dark years of its aftermath. Politically, Thailand's road has been a long one. An evolving democracy has been forged out of 17 military coups, many of them violent. Some leaders have proved corrupt on a grand scale, stripping once extensive forests and natural resources for their own ends. Through all the pressures, King Bhumibol has been the one unifying strand, guiding his nation through times of trouble. His authority has been nurtured through the years by a personal life considered exemplary, marked by a commitment to work, traditions and the rural poor. His delicate exercise of that moral authority is widely considered to have made the monarchy more relevant to all Thais and helped the nation's political progress. Speak to ordinary Thais and it is clear the king is beyond a mere figurehead. To most, the 78-year-old embodies the Thai trinity - nationhood, religion and the monarchy. His image is omnipresent, adorning homes, offices and buses. People wear his image around their necks and carry it in their wallets. Rush-hour train crowds and cinema-goers stand in silence to daily broadcasts of the national anthem, written by the king himself. His reign began in a very different time for the monarchy. Just 19, he became king after his elder brother died of a gunshot wound in circumstances that remain unexplained. His uncle, King Prajadhipok, had abdicated 11 years before following a military coup that ended the absolute monarchy. Born in the American city of Boston, he lived in Switzerland before returning to Bangkok in 1950 when he was crowned the ninth Rama king of the Chakri dynasty. Yet another military coup in 1957 saw the young king embark with his wife, Queen Sirikit, on extensive missions to the countryside, visiting Thailand's poorest, most traditional communities. His relationship with all levels of society has become a defining characteristic of his reign. Over the years, his interests in the sustainable development of agriculture have also proved a constant. Hundreds of photos over the years show him toiling among the peasants, sitting down with them in conversation about how to improve their lot, or wading through irrigation channels to inspect dams. One of the most common images of the king found in offices and homes across Bangkok shows him working in the countryside, map in hand and camera around neck, beads of sweat dripping from the end of his nose. Part of his palace in Bangkok has been given over to development of new rice strains and sustainable crops - a mission he continues to this day. He has encouraged his three daughters and one son, Crown Prince Maha Vajiralongkorn, to continue the efforts. The king's highly popular second daughter, Crown Princess Sirindhorn, has been particularly active. Other images from the past illustrate another side to the king - jazz musician, internationally competitive dinghy sailor, artist. In the 1960s, the royal couple travelled the world, raising an emerging Thailand's profile across Europe, the Americas and Asia. It wasn't all statecraft. Another popular iconic image shows the king of Thailand meeting the king of rock and roll, Elvis Presley, on the set of GI Blues at the height of the rock star's power. One US trip included a private visit to the Manhattan apartment of jazz great Benny Goodman. For two hours, he played with Goodman and his sidemen, including Urbie Green and Red Norvo, having met them during performances in Bangkok. 'To be called a 'cool cat' and for it to be said he could join their bands if ever he 'needed a job' were meant as great compliments, which without a doubt, His Majesty accepted as such,' one official biography notes. Over the decades, King Bhumibol's interest in constitutional development grew. The nation's political development remained largely in the hands of the military establishment's officer classes. In 1973, he staged the first public intervention of his reign to bring an end to violence that erupted on Bangkok's streets when a military government opened fire on protesting university students. The prime minister, Thanom Kittikachorn, and other military leaders fled into exile, and the king backed moves towards democratic rule, despite widespread fears about the spread of Indochinese communism into the kingdom. Thanom, wearing a monk's robes, returned from exile three years later, fuelling tensions roiling in newly democratic Thailand since communist victories in neighbouring Laos, Cambodia and Vietnam the year earlier. Right-wing groups surged into the campus of Thammasat University where protests were gathering steam. Students were lynched, burned and shot, and thousands were arrested. A military coup that night ended the democratic experiment and restored law and order. The king later appointed a Supreme Court judge to rule as a civilian prime minister. Despite ongoing constitutional debates, it would be 12 years before Thailand returned a democratically elected prime minister. The king expressed disapproval when that political leader, Chatichai Choonhavan, was overthrown in 1991. That was the first act in what would prove to be one of the defining moments of his reign - his dramatic intervention in May 1992 that still resonates today. The junta of General Suchinda Krapayoon had seized power back from an interim government. His troops turned their guns on protesters led by the ascetic former general Chamlong Srimuang, now leading action against Mr Thaksin. Bangkok descended into bloody chaos. In footage recently re-aired on Thai state television in an apparent bid to cool current temperatures, the king publicly summoned generals Suchinda and Chamlong. Forced by protocol to prostrate themselves before him, they were told to peacefully settle their differences for the sake of the kingdom. Suchinda promptly resigned and fresh elections took place in September 1992 - producing a victory for Chuan Leekpai's reform-minded Democrats. It was Thailand's last military coup. The Democrats also helped restore stability in Thailand in the wake of the 1997 financial collapse. They played a key part in pushing through a landmark constitution to get the black money out of Thai politics and create a more stable system. The king was active behind the scenes, telling one cabinet that they should not dither with the document. 'You should move more quickly for the stability of the country's administration and the people's happiness.' That document remains Thailand's political cornerstone. If last Sunday's poll fails to produce a parliament that can legally convene, Article 7 provides room for the king to act to create an interim government. At times, the king has briefly entered the political arena to stop inter-departmental squabbling - mere public expressions of concern from his Privy Council advisers can be enough to bang political heads together during moments of tension. At other times, his social messages can be far more subtle. Four years ago he produced a most unusual tale - Biography of a Pet Dog. It told the story about a street dog he rescued from the pound after being alerted by concerned residents on a visit to a poor Bangkok neighbourhood. He was later presented with a puppy as a gift, the wailing mongrel immediately growing calm in his presence. Tongdaeng (copper) became a loyal friend, accompanying the king around the palace and riding with him in his car. 'Dogs from the street can have all the desirable qualities one could want from pet dogs,' he wrote. 'Most adopted stray dogs are usually humble and exceptionally faithful to their owners as if they are grateful for this kindness.' The book sold out in days.