The offending involved two young victims and occurred over a period spanning 1980 to 1991. The victims' names and anything that can lead to people knowing who they are are automatically suppressed, something Justice Toogood reinforced yesterday.
The victims, now grown men, were in the public gallery throughout the lengthy sentencing process which included several hours of complex legal discussion relating to whether, under law that existed at the time of the offending, both were entitled to receive reparation for emotional harm.
Because the charges are so historic the judge said he had no alternative but to sentence Buchanan under legislation that existed at the time of his offending which meant he couldn't impose a minimum period of imprisonment. He said if Buchanan was to be sentenced under today's legislation he could have been jailed for about 20 years.
He outlined how Buchanan had abused the two boys in various places, including while they were camping with him.
When their family moved to another region he followed and further offending against the younger victim occurred there. He noted a lot of the offending was when Buchanan was drunk.
He said both the victims were terrified of Buchanan who abused the older boy when he was aged between 7 and 12 and began abusing the younger when he was 4.
He said Buchanan treated the older boy as his girlfriend, sodomising him on numerous occasions.
He described how Buchanan psychologically pressured the boy into 'games' with him. When the child got older and stronger and attempted to resist him, Buchanan put his hands around his throat, violently choking him.
He was so sexually aggressive against the younger child he thought his genitals were being ripped off.
Both boys were so badly hurt by Buchanan they bled from their anal areas and one went to school with toilet paper in his underpants to stem the flow. Both suffered prolonged and extreme pain.
The judge said Buchanan had been careful not to hit the boys where bruising would be noticed by adults.
He told Buchanan he had robbed his victims of their childhoods and normal sexual development. Both had undertaken lengthy counselling at considerable cost.
One had said he felt so useless and disgusted he had contemplated suicide when he was 8. The other admitted also contemplating taking his life.
Neither had told the other what had happened until one went to police in recent years and alerted the other that Buchanan was to be arrested.
The judge offered the men his deepest sympathy.
"I admire the courage you have shown by coming forward and I particularly want to acknowledge the restrained and careful way you gave evidence without exaggeration, that is to your credit."