Saudi Arabia named Prince Salman bin Abdulaziz to be crown prince Monday, the state news agency reported, putting him next in line to the throne of the oil-rich kingdom.
His appointment comes a day after burial services for Crown Prince Nayef bin Abdulaziz, whose death was announced Saturday.
He became defense minister in November.
Salman's official biography on the website of the kingdom's Interior Ministry says he had memorized the Quran by the age of 10.
Nayef, a hard-line conservative credited with pushing back al Qaeda, was interior minister as well as crown prince. Prince Ahmed bin Abdulaziz is replacing him as interior minister, the Saudi Press Agency said.
Nayef was named crown prince in October by his brother, the king.
Saudi state TV, which reported his death Saturday, broadcast Quran readings as an expression of mourning for the prince, who died in Geneva, Switzerland. He was in his late 70s.
"It is a shock. We all knew his health was frail, but his death is a shock," Saudi Foreign Ministry spokesman Osama Nogali said. "We still don't know the reason behind his death."
Abdullah attended the funeral, along with Gen. Hussein Tantawi, the head of Egypt's Supreme Council of the Armed Forces.
U.S. President Barack Obama released a statement Saturday offering his condolences.
"Under his leadership, the United States and Saudi Arabia developed a strong and effective partnership in the fight against terrorism, one that has saved countless American and Saudi lives," he said.
He praised Nayef for supporting a broad partnership between Saudi Arabia and the United States.
U.S. Vice President Joe Biden similarly offered his condolences and hailed the former leader as an important ally in the fight against terror.
Nayef had been Saudi interior minister since 1975, overseeing the kingdom's counterterrorism efforts. He also was deputy premier.
A classified U.S. Embassy cable leaked by the website WikiLeaks described Nayef as a hard-line conservative who was lukewarm to King Abdullah's reform initiatives.
Nayef led the crackdown against hard-line Islamists who took control of Mecca in 1979 and also oversaw the smashing of Saudi-based al Qaeda cells in the early 2000s.
In recent years, his son, Prince Mohammed bin Nayef, led the kingdom's fight against al Qaeda as the elder Nayef seemed to have taken more of a back seat.