The Supreme Court of Canada has ruled that aboriginal background should be a paramount consideration when sentencing violent offenders who have breached long-term supervision orders.

In a 6-1 decision, the justices ruled on a pair of cases in which offenders on long-term supervision were sentenced after violating the terms of their orders.

Both men had long, violent, criminal histories.

The justices said the issue of aboriginal background must be considered even in cases where the accused have been placed under long-term supervision by the courts.

"To be clear, courts must take judicial notice of such matters as the history of colonialism, displacement and residential schools and how that history continues to translate into lower educational attainment, lower incomes, higher unemployment, higher rates of substance abuse and suicide and, of course, higher levels of incarceration for Aboriginal Peoples," Justice Louis LeBel wrote for the majority.

"Failing to take these circumstances into account would violate the fundamental principle of sentencing."

The ruling marked the first time the court has ruled on how the Gladue principles, guidelines set by Parliament on aboriginal sentencing, are to be applied in cases involving long-term, violent offenders.

Those Criminal Code provisions are not a "race-based discount on sentencing," LeBel wrote.

They are a "remedial provision designed to ameliorate the serious problem of overrepresentation of Aboriginal People in Canadian prisons and to encourage sentencing judges to have recourse to a restorative approach to sentencing."

In one of the cases, a man who breached an order to abstain from alcohol and was sentenced to three years for the breach had his sentence cut to one year.

Manasie Ipeelee was caught cycling drunk in Kingston in August 2008 and pleaded guilty to breach of his order. His three-year sentence was upheld by the Ontario Court of Appeal until it was overturned Friday by the Supreme Court.

Ipeelee's adult record contained 24 convictions, including sexual assault.

In the other case, the justices rejected a Crown appeal which wanted a stiffer sentence for an offender who was caught using cocaine and morphine at a halfway house in Vancouver.

Last year, the British Columbia Court of Appeal judge reduced Frank Ladue's three-year sentence for breaching a court order to one year.

His record lists more than three dozen convictions, including robbery and sexual assault.