The musician confirmed Bob died on Tuesday (UK time) just weeks after the singer’s eldest sibling Don died and Rod shared his agony in a heartfelt statement in which he declared he has lost two of his “best mates in the space of two months”.
The 77-year-old musician wrote: “It’s with great sadness that I announce the loss of my brother Bob last night, who joins my brother Don on the great football pitch in the sky.
“I’ve lost two of my best mates in the space of two months. RIP Don and Bob ‘irreplaceable buddies’ Sir Rod Stewart.”
The music star – who also has two sisters named Peggy and Mary – did not give a cause of death in his statement.
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Rod previously revealed his brother Don had died aged 94 in September two days before the death of Queen Elizabeth.
He shared the sad news in a post on Instagram and Twitter, writing: “It has been a devastating 48 hours.
“We lost my brother Don on Tuesday at 94 and today we have all lost Her Majesty Queen Elizabeth II at 96.”
Sir Rod went on to pay tribute to the Queen in the same post, hailing her as an “unwavering presence” throughout his life and calling her “a great unifier” – like his older sibling.
He added: “The Queen has been an unwavering presence throughout my life and a great unifier.
“A shining star that will never fade in our hearts and souls.”