His billing was worthy of a children's story. A "man of big brain and good heart" was promised by Edinburgh International Book Festival director Catherine Lockerbie. The audience members braced themselves for a character worthy of AA Milne. Instead we got the textbook prime minister: worthy, knowledgeable and a bit wordy.

Gordon Brown's "mystery" appearance was the opening event of the 25th Book Festival. For a head of government, Brown's literary credentials are impressive. Not only has he written a short story for children and published several works of non-fiction, he recently compared himself to Wuthering Heights' anti-hero Heathcliff.

Despite the weather rattling the tent throughout, Brown seemed genuinely relaxed as he was interviewed by fellow Edinburgh University alumnus, Ian Rankin.

Brown's choice of how to spend this weekend was fitting for a man not known for pyrotechnics, verbal, literary or otherwise. He swapped a balmy evening in Beijing watching what many have dubbed the greatest show in history in the company of 90,000 others for a cold, wet morning in a tent with 500 of Edinburgh's well-read.

Thousands of similar souls have already helped sell out 30% of the Book Festival's events, including appearances by Sir Sean Connery, Salman Rushdie, and Margaret Atwood.

Wearing beige slacks, navy blazer, and open-necked light blue shirt, Brown sadly didn't reveal if he rated the writings of his foreign secretary, nor did he talk about when he might start penning his own memoirs of his time as prime minister. Instead he quoted from such literary figures as Mark Twain and John Buchan, as well as figures such as Archbishop Desmond Tutu, Nelson Mandela, and his father as he addressed his main themes of "courage, global citizenship and Britishness". Hardly a tag line for an airport novel, but certainly something that would have pride of place on Brown's bedside table.

Domestic politics were touched upon briefly. His argument for maintaining the union between Scotland and England, that of shared values, environment and people, was nearly drowned out by a particularly vicious downpour and a bellow of bronchial wind.

The test to see if even the weather has swung towards the SNP will be when Alex Salmond appears later in the festival.

Rising knife crime is something else that unites the two kingdoms. Once the wind died down, the prime minister said society needed to make carrying them as unacceptable as carrying guns.

But like a Victorian Church of Scotland missionary, Brown spent a lot of time discussing the needs of the wider world. Burma particularly animated him, and he returned to the topic several times. He told the story of the pro-democracy campaigner Aung San Suu Kyi, to whom he dedicated a chapter in his recent book Courage: Eight Portraits. He related the tale of her father's assassination, her husband's death from cancer, and her choice to remain in a country knowing she would be arrested, like a slightly muddled bed-time tale, but one that he hopes had a happy ending. "By the time I am finished in politics I want to see Aung San Suu Kyi not only released but in power in Burma," he said.

When asked about the presidential race in the US, after a fiddle of his cuff-links and a knowing smile, Brown hedged his bets. "They are two courageous people," he said. He praised Barack Obama's drive to re-engage the US with the world, while describing John McCain as "one of the great military heroes of our time".

He closed the session by returning to one of his great sermons: Africa. Helping the continent, he said, should not be put on hold because of our domestic financial issues. Fostering a green revolution on the continent and providing education is of vital importance to prevent other nations and extremist groups exploiting the already exhausted lands. China and extremist Muslim groups were mentioned as two particular bogeymen stalking Africa, like villains lurking in the shadows of Rankin's novels.

And with that he was off to continue his summer break. He might have passed on the opening of the Olympics, but as he left he didn't rule out catching the start of Raith Rovers' season.

Later at the Book Festival yesterday, historian Ilan Pappe, writer Raja Shehadeh and artist Jane Frere reflected at a sell-out session on the importance of the event known to Palestinians as Nakba, or catastrophe - the time they were forced into exile as the state of Israel was born in 1948.

Pappe, described by journalist John Pilger as Israel's "bravest" and most "incisive" historian and reviled by many within the Israeli establishment as public enemy number one for his views, spoke eloquently about the need for Israel to come to terms with its actions during 1948.

Shehadeh, who recently won the Orwell Prize for political writing for his book Palestinian Walks, put the Nakba into a contemporary context, insisting that the process of ethnic cleaning was in effect still under way but "by different means".

Shehadeh is something of a favourite among audiences at the book festival. His diary account of his time under Israeli military siege in Ramallah, When The Bulbul Stopped Singing, was adapted for the stage in Edinburgh a few years ago.

Artist Jane Frere, while admitting to feeling "a bit like an imposter" at the Book Festival as she has not actually written a book, brought a fresh voice and eye to the session, which no doubt will have many in the audience making their way to the Patriot Hall Gallery in Edinburgh to see her own interpretation of the Palestinians' 1948 exodus in her sculptural work Return of the Soul.

Additional reporting by David Pratt