Updated

Retirement is not traditionally on the cards for queens, kings or popes, but a string of abdications in recent months, some unprecedented, show many are choosing to step aside instead of labouring on until death.

Belgian King Albert, 79, became the latest to announce he will abdicate his throne, a little over a week after the emir of Qatar Hamad ben Khalifa Al Thani stepped down in favour of his son -- a first for an Arab country.

"For certain duties, which we thought ended with death, we now see a modern logic: abdication is possible," Belgian political analyst Pascal Delwit told private television station RTL-TVI.

The abdication of queen Beatrix of the Netherlands in April was not a complete surprise, as both her mother and grandmother before her voluntarily gave up their crowns.

However a decision by Pope Benedict XVI to step down that same month stunned the world. He was the first to resign the papacy -- an elected monarchy -- in some 600 years.

In a nod to modernity he said that "in today's world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith" he no longer had the strength of mind and body to do the job.

Benedict's predecessor John Paul II hung on, stricken by Parkinson's disease, as the child sex scandal and corruption which would eventually dog his own rule mounted in the Vatican.

Many other monarchies have been rocked by scandals, including that of Belgium's Albert who has faced a court case over his paternity of an illegitimate daughter and a financial scandal over taxes

"These last 15-20 years the monarchy has evolved, it depends more and more on the popularity of the sovereign in place," said history professor Willem Otterspeer at the Leiden University in the Netherlands.

"In this context it is better to retire at the right moment, instead of wanting to hold on to the end and attract negative publicity."

But not all seem open to stepping down, such as Spain's 75-year-old King Juan Carlos, who has ruled it out despite numerous ailments and his family being mired in corruption scandals.

Analysts say he is unlikely in the short-term to hand over to his son Felipe, who has taken a bigger role lead in official royal functions over recent months, as it could be seen as abandoning his duties while his country is in the grips of an economic crisis.

In the United Kingdom, Europe's oldest monarch Queen Elizabeth, 87, shows no intention of handing over power to her son Charles, 64 and is seen as taking her vows to rule until death as irrevocable.

"Elizabeth's attitude is clearly that from another time," said Otterspeer of the queen who has been in the throne for 60 years.

Scandinavian monarchs show no sign of retiring in Sweden or Norway, while Denmark's 73-year-old Queen Margrethe II has assured she will stay on her throne until her death.