Pope Francis today offered this morning's Mass at Casa Santa Marta for his predecessor, Pope Emeritus Benedict XVI, who celebrates his 88th birthday today.

"I would like to remind that today is Pope Benedict XVI's birthday. I have offered the Mass for him and I also invite you to pray for him, so that the Lord may sustain him and give him much joy and happiness," the Holy Father said this morning.  

According to Vatican Radio, the Pontiff Emeritus will quietly celebrate his birthday at Mater Ecclesiae monastery at the Vatican, where he lives a life of prayer and reflection following his resignation from the papacy.

Pope Francis has made no secret of his love and admiration for his predecessor, who he has likened to a "wise grandfather".

“It’s like having your grandfather in the house, a wise grandfather. Pope Benedict is a man of great prudence.  He doesn’t interfere!  I have often told him so: 'Holiness, receive guests, lead your own life, come along with us,'" Francis said in a press conference on his return flight from Brazil in 2013.