Paolo Gabriele's sentence was reduced to 18 months from three years because of mitigating circumstances, including that Gabriele had no previous record, had worked for years for the Holy See.
Gabriele also acknowledged that he had betrayed the Pope and was convinced, "albeit erroneously" that he was doing the right thing, according to Judge Giusppe Dalla Torre.
Gabriele was accused of stealing the pope's private correspondence and passing it on to journalist Gianluigi Nuzzi, whose book revealed the intrigue, petty infighting and allegations of corruption and homosexual liaisons that plague the leadership of the Roman Catholic Church.
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Outbreaks of rain and strengthening winds will affect southernmost parts of England and Wales today.
An earlier debate on the issue was suspended as an 'expression of support' following the Westminster terror attack.
Five people were killed and dozens more were injured after a car and knife attack in the capital on Wednesday afternoon.