The pope's brother said on Monday he has known "for a few months" that Benedict XVI was planning to resign and confirmed that the 85-year-old pontiff was "feeling the burden of his age".
Georg Ratzinger told AFP: "The reason for his resignation is indeed that he is feeling the burden of his age... I have known for a few months that this (the resignation) was planned."
"He knows the demands of the office. I think his decision is correct. It is a positive thing that he is handing over the office to younger hands," said Ratzinger, four years the pope's senior.
He also confirmed that Benedict XVI would remain in Rome.
"I am in Rome three times a year. On this Rome trip, we will be able to spend some more time together," Ratzinger said.
Benedict XVI was born Joseph Ratzinger on April 16, 1927, in Marktl am Inn, in the predominantly Catholic southern German region of Bavaria.
He was ordained priest at the same time as Georg in 1951, and began teaching theology at Freising College in 1958.
Ratzinger went on from there to teach at several other German universities, notably in Bonn, Muenster and Regensburg.