Pope Benedict XVI, who took office in 2005 following the death of his predecessor, John Paul II, said today that he will retire at the end of this month. He will be the first pope to step down voluntarily in six centuries.

The German-born pontiff, 85, said in a statement that after examining his conscience, he had decided that he was simply too old to continue.

“Before God, I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of my position as head of the Roman Catholic Church,” he wrote.

Danish Catholic Bishop Czeslaw Kozon was shocked, as were many other Catholics around the world, by the announcement.

“Pope Benedict is popular and well-liked,” the Bishop told Politiken newspaper. “He will be remembered as a great theologian and preacher, who managed to convey the Catholic faith clearly."

A call for comments on the pope's retirement on The Copenhagen Post's Facebook page included expressions of shock, well-wishes for the departing pontiff, joy that he was stepping down and at least one accusation that the paper was fishing for a Dan Brown-esque conspiracy theory.

Resignations from the papacy are not unknown, but the modern era has been marked by pontiffs dying while in office. The last to step down was Gregory XII in 1415.

At 78, Benedict was already one of the oldest new popes in history when he was elected in 2005. He was considered a theological conservative, with uncompromising views on subjects like homosexuality and female priests, and his papacy has been both conservative and contentious. He took over as one of the fiercest storms the Catholic Church has faced in decades – the scandal of child sex abuse by priests – was beginning to see the light of day.