Israel's Supreme Court has partially accepted an appeal from former Prime Minister Ehud Olmert and reduced his prisoner sentence from six years to 18 months.

The court announced on Tuesday that Olmert will begin serving his sentence on Feb. 15. He will become the first Israeli leader to ever serve behind bars.

The 70-year-old Olmert was convicted in March 2014 in a wide-ranging case that accused him of accepting bribes to promote a controversial real-estate project in Jerusalem and sentenced to six years.

He was charged for acts that happened while he was mayor of Jerusalem and the country's trade minister, years before he became prime minister in 2006.

Olmert has denied any wrongdoing and was allowed to stay out of prison until the verdict on his appeal was delivered.