Cuba marked Fidel Castro's 86th birthday on Monday with congratulatory messages in state media but no planned appearance by the retired leader, who has faded from public view.

Communist Party newspaper Granma published memories of Castro from people familiar with him such as Cuban journalists and cohorts from the 1959 revolution. Government-run websites carried essays on his life and best wishes from presidents Evo Morales of Bolivia and Daniel Ortega of Nicaragua.

The milestone was yet another reminder of both the Cuban leader's longevity and his inevitable mortality. He survived in power for nearly 50 years despite numerous attempts on his life and periodic rumors of his passing.

Castro seemed to reflect on his mortality in a letter to his friend and ally Hugo Chavez in July, when the Venezuelan president turned 58.

"Fifty-eight years is nothing, Hugo," Castro wrote in the letter, which was posted online by Venezuela's office of the presidency and reproduced by Cuban website Cubadebate. "I, who am almost 28 years older, have lived a great part of the last 100 years and can testify as to the meaning of time."

Castro stepped aside temporarily in 2006 due to an illness that he later said nearly killed him. In 2008 he left the presidency permanently and younger brother Raul, who turned 81 earlier this year, took over.

The exact nature of Castro's illness was never revealed and the status of his health is kept secret, but media reports said it was complications from diverticulitis, an intestinal ailment common in older people.

It has been nearly two months since Castro published one of his semi-regular opinion columns titled "Reflections," which have often been lengthy essays on international politics. Before falling silent in late June, they had taken on the form of short, sometimes cryptic messages.

In one of the mysterious mini-"Reflections," Castro wrote about something called the "FC" without explicitly saying what they were. Others marveled at yoga masters' flexibility, extolled the nutritive virtues of a tree known as moringa and reproduced six lines of poetry about Ernesto "Che" Guevara.

Castro last appeared in photos and video in March, looking jovial but thin and pale as he and companion Dalia Soto del Valle greeted a visiting Pope Benedict XVI.

Castro has gone silent for extended periods in the past, but each time he does the rumors once again begin swirling.

"Has Cuba converted Fidel Castro into a virtual figure?" opposition blogger Yoani Sanchez tweeted. "He doesn't appear, but they tell us he's still alive."

Either way, Castro doesn't seem to have much of a hand in running the country, though he has publicly voiced approval for Raul's program of economic reforms and the younger Castro says he consults with his brother.

But his outsize persona ensures that Fidel is never far from people's minds.

"Just his being there, alive, gives people a lot of strength to keep working and fighting," said Gerardo Cartaya, a 53-year-old self-employed cab driver in Havana.

On Monday, cultural centers organized small concerts in honor of the "comandante," and an art show in the Plaza of the Revolution depicted moments in Castro's life from childhood to his arrival as one of the most recognized figures in Latin American history.

The Union of Communist Youth held a small party with a cake and children singing Cuba's version of the "Happy Birthday" song.

"Every time I meet with Fidel I feel like I have had to stand up and defend him against whatever they might want to do to him," famed Cuban ballerina Alicia Alonso was quoted as saying in Granma's collection of memories. "Every time I meet with him I feel nervous."


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