Phil married Kay in 1966. The pair welcomed four sons, Alan "Al" Robertson, Jase Robertson, Willie Robertson and Jep Robertson, during their decades-long marriage.
Their brood was featured on the A&E television series Duck Dynasty, which aired from 2012 to 2017, and followed their lives as they operated Duck Commander, a family business that manufactured duck calls and other hunting-related products.
Phil shocked fans by revealing during a 2020 interview that he had an adult daughter from a previous affair in the '70s. Phil's son Alan explained he and his brother Jase received a letter from a 45-year-old woman named Phyliss, who claimed to be their sister. "So basically, it was from a woman who said that by a DNA search, she thinks that dad might be her dad," the reality star explained on the "Unashamed" podcast, adding that he initially "dismissed" the letter because the woman's birthday was after the time Phil had become a dedicated Christian.
However, after learning she had no financial motivations and that she's also a Christian, Alan was more inclined to tell his parents of his possible sibling. "Once we get into that and start looking at it a little more deeply, I'm like, 'Oh woah, woah ... there might be something to this,'" Al said.
The results of the DNA test revealed a 99.99 percent match between Phil and the woman. "It's a pretty cool explanation of redemption, reconciliation, love," Phil told listeners. "As it turns out, you have a daughter that you don't know about and she has a father she doesn't know about, 45 years doesn't sound like very long, but you see, that's a while."
Jase and Al announced in December 2024 that their father was "not doing well" and had been diagnosed with early-onset Alzheimer's disease during an episode of their "Unashamed" podcast.
Jase explained his dad still wanted to participate in the podcast - which the duo launched in 2018 - but that his memory was starting to decline.
"I was like, 'You know, your memory is not what it once was.' He's like, 'Tell me about it.' So, he is literally unable to -- I think he would agree -- to just sit down and have a conversation," he told listeners about his father.
In addition, Jase explained that doctors told his father he had "some sort of blood disease" and it was "causing all kinds of problems." Al said his dad had been suffering from the unnamed illness for "years," but noted it had recently "gotten a lot worse."
Weeks later, Willie gave an update on his father's condition to Fox News, telling the outlet Phil was "battling many different things at the same time."
"He's got a blood disorder, and then he's got the mental issues that could be early [onset] Alzheimer's ... and probably some ministrokes because of his blood," Willie explained on December 17, 2024. "And so, it could be some stroke stuff happening, that has happened. So, we're still checking on all that. But then he also has a back issue, he's fractured his back and that's where the pain's at. So, he's kind of battling many different things at the same time."
In addition to the blood disease and back problems, Willie revealed Phil had an "enlarged spleen, which could be pushing on the stomach," resulting in a loss of appetite.
The Duck Dynasty alum's family is rallying by him and ensuring the patriarch isn't alone as his health declines.
"They want to give him the best life they possibly can under the circumstances and check in on him often and take him out for drives in the woods to reminisce about the good old days and make sure he's getting the best care," the insider exclusively told In Touch about his loved ones on January 20, 2025.