They were mostly dismissed as the rantings of a madman - a blizzard of letters directed to everyone from the Queen of England, the boss of Australia's domestic spy agency, prime ministers and even then Senator Barack Obama.

From 2007 to 2010, Sydney siege hostage taker Man Haron Monis appeared desperate to come to the attention of authorities via a tireless letter writing campaign regularly discussing terrorists and terrorism and lashing out at the war on terror.

Every week for years he fired off correspondence to politicians, police, public officials, media outlets and prominent members of the Muslim community and then published the responses on his website, according to copies of the letters obtained by Fairfax.

His rants focused on a diverse array of conspiracy theories about the treatment of muslims, the killing of civilians by Australian soldiers in Afghanistan, a so-called plot by the Liberals to let off bombs in Australia and blame Muslims, suicide bombings and the failure of St George bank to sack a staff member supposedly involved in a racist attack.

Some of the recipients replied cautiously, others ignored his letters and were then subjected to a blast on his website and a demand for response.

No one was immune from his correspondence  - not even the Queen, who in early 2008 was sent a letter in relation to what he alluded to were problems in Australian society.

He noted he received a "polite signed letter" from the Queen's senior correspondence officer Sonia Bonici, who had passed on his letter to the Governor-General of Australia in May 2008.

"Thank you again for taking the time and sending a polite signed letter," he later noted in a reply.

However his mild response soon became hysterical when the governor-general was unable to help.  In June 2008 he fired off a missive to then Senator Barack Obama accusing him of hiding his religion and urging him to trust in God and admit he was a Muslim.

"You will be president but this is a test from God to show that Senator Barack Obama chooses the right path or the Satanic tactic," he wrote. No reply seems to have been forthcoming.

In 2007 he appeared convinced the Liberal Party was behind a series of explosions designed to discredit Muslims, he alleged in another series of letters.

In 2008, he fired off letters to police and government officials alleging a racist attack should have been investigated as terrorism.

He received a generic reply from AFP Commissioner Mick Keelty's chief of staff Roman Quaedvlieg thanking him for his correspondence to the commission and stating if he had any information about the commission of offences he should contact Crime Stoppers or the National Security Hotline or NSW Police.

It noted the AFP was unable to assist further with the issues raised.

In 2008 he was fixated by the civilian casualties from Australia's operations in Afghanistan and demanded an investigation by the Defence Department.

On May 22, Defence Minister Joel Fitzgibbon's chief of staff Daniel Cotterill replied thanking him for the letter and directing him to a report that Defence had already provided into the incident.

Throughout his ramblings were constant references to terrorists and acts of terrorism.

He wrote to Attorney-General Robert McClelland in late 2007 asking would Australian Muslims be wrong to praise Osama bin Laden.

"I mention the statement of one of our Muslim brothers in the Australian Muslim community forum: 'I love how they sensationalise the statement. What is so strange about him saying that Osama Bin Laden in a lovely brother? Even non-Muslims who have met him have said that he is a very humble person.'

"Dear Attorney General, I really need to know whether it is against the law if we describe Osama Bin Laden".

In July 2007, he wrote to the Commonwealth Director of Public Prosecutions Damian Bugg mentioning a bomb going off at a train station and claiming Channel Seven's Sunrise program was inciting terrorism.

His reasoning seemed to be that Seven's report on the Glasgow Airport's terror attacks in 2007 had mentioned a hypothetical scenario that could inspire terror attacks.

The same month he wrote to then Director-General of Australia's Security Intelligence Organisation head (ASIO) Paul O'Sullivan.

He wrote that he had witnessed the indirect instruction for terrorists and he had sent a report via express post to Mr O'Sullivan. But then he railed that "I still haven't heard from you". Later he reported ASIO did reply but he did not post the reply.

In November 2008 he wrote an open letter to the families of executed Bali bombers saying "congratulations for having a martyr in your family. We should celebrate when a Muslim joins the martyrs".

But the letters that eventually saw him investigated and charged however were those he sent to the families of Australian soldiers killed in Afghanistan, suggesting the soldiers were murderers.

In 2008 he was charged with harassment and eventually convicted. Three days before the deadly Martin Place siege, the High Court dismissed his bid to overturn his conviction.