A judge in Egypt's Supreme Constitutional Court, Adli Mansour, has been named interim president, and will reportedly be sworn in on Thursday.
Mr Mansour was born in 1945 and trained as a lawyer.
He served for many years in Egypt's State Council, which provides legal advice to the government. He is also believed to have spent three years in Saudi Arabia with the Egyptian ministry of commerce.
In 1992, he was appointed to the Supreme Constitutional Court - a body that has remained largely unreformed since President Morsi was elected and clashed with him many times.
He was appointed chief justice of that court on 1 July, just days days before being named interim leader.
The Muslim Brotherhood tells ITV News they are against violence but will "pay the price of their blood" to restore their ousted president.
Egypt's army has named two further officials in the transitional government as its supporters and opponents vowed to stay on the streets.
There has been outrage in Egypt after 51 people were killed near an barracks where ousted President Mohamed Morsi is thought to be held.