This week, a man scaled the fence of Buckingham Palace, evaded CCTV and heat sensors and ended up just metres away from where the Queen was sleeping, according to British TV.
It was the second security breach in the last year — in July 2018, a homeless man broke into the grounds of the Palace and went undetected for four hours.
However, threats to the monarchy don't just try and climb over gates.
Right now, the case could be made that the Duke and Duchess of Sussex qualify as a greater threat to the monarchy, whose global popularity and burgeoning international brand have thoroughly upset the royal pecking order.
Because, the Windsors are a family and they are not. While the clan might gather for weddings and christenings — a cheerful chattering gaggle all in $2000 Philip Treacy hats — they operate within a strict hierarchy.
Members labour in the knowledge that their competing interests must be subsumed in the pursuit of their collective goal of constantly shoring up the monarchy.
Translation: Being a member of the royal family requires putting the interests of the crown ahead of your own.
You get to wear a tiara so suck it up.
While having glittering charismatic younger members is essential to maintaining public interest in the monarchy, that should never come at the expense of detracting from the person who actually gets to wear the crown.
Whether Diana was just being wilfully obstinate in the face of her husband's imperious family or simply naive, the causes and issues she devoted herself to in the '90s transformed her into a global powerbroker who, perhaps unwittingly, stole the limelight and made herself a target.
And this was a cardinal sin in the eyes of the royal family — and one her son and daughter-in-law are dangerously close to repeating.
As the Princess' equerry of eight years Patrick Jephson has written: "As Diana discovered to her cost, if you acquire for yourself, however justifiably, a profile, a purpose, and a vocal, passionate public devotion independent of the royal mainstream, then you will risk being perceived and presented as a threat to the Crown itself.
"This will mobilise the full forces of the establishment against you."
Basically, she was a victim of her own success and the Sussexes are perilously close to repeating this miscalculation.
This week, Harry and Meghan were named to Time's 25 Most Influential People On The Internet, reflecting their incredible digital sway (9.1 million Instagram followers and counting). Later this year, they will head to South Africa for their first tour as a family where they are expected to formally launch the Foundation of the Duke and Duchess of Sussex with a focus on community and the environment.
This will most likely be just the beginning of the couple's renewed global push to cast themselves as international activists par excellence.
And you know what? It will work. They are smart, photogenic and determined, and that is why they will be a problem for the monarchy. Their very popularity sucks up oxygen, and thus there is nothing left for the hoary edifice that is the crown.
Every Netflix special and meeting with Oprah ensures the focus will stay on them, and not whatever the monarch (or future monarchs) are doing.
Consider this. Within the same 24-hour period earlier this week, the Prince of Wales, Duke of Cornwall and the Duchess of Cornwall visited Mevagissey (it's in Cornwall) and later Charles visited Boscastle to celebrate the 60th anniversary of the Cornwall Area of Outstanding Natural Beauty.
And, the Duke and Duchess of Sussex went to The Lion King premiere, hugged Beyonce and nearly broke the internet. Which one do you remember reading about?
It would be wildly naive to think two 70-somethings dutifully plodding around Cornwall admiring local pasties would trump the goings on of the controversy-plagued Sussexes. But the grave imbalance in coverage and attention will be duly noted by those entrusted with ensuring the continuation of an institution which can trace its lineage back to Egbert in 827. (Seriously).
"The one really key skill Meghan absolutely must perfect is how to avoid being seen as any kind of a destabilising danger to the established royal order," Patrick Jephson writes in The Meghan Factor.
"Centuries of royal history have shown that, when you're in the dynasty business, every consideration is subjected to the ultimate existential test: Will this person/thing/idea/development help or hinder the survival of the current royal line?"
In the years and decades to come, the Sussexes' endeavours will only increasingly compete with those of the Cambridge's. Every click, like and column-inch devoted to the Sussexes and their global endeavours will come at the expense of the future King and Queen Consort.
Strange as it might sound, there is a certain amount of persistent campaigning required to keep the monarchy alive and kicking. And to do that, they need persistent coverage, column inches and clicks. Anyone who sucks all the media focus away from Charles, Wills and later, George, will be viewed as an existential threat.
The monarchy is a resilient beast whose longevity is down to a slavish commitment to the overriding principle that the only thing that truly matters is the monarch and those in the line of succession.
So … God Save the Queen (and the future Kings).
And god help the Sussexes because things are going to get rocky in the years to come.
This article was first published on news.com.au.