Bodies interred in the Royal Vault at St George’s Chapel, Windsor Castle, are sealed inside lead-lined oak coffins and placed above ground in a stone chamber beneath the chapel floor. The lead lining creates an airtight seal that, combined with embalming, slows decomposition dramatically compared to a standard burial. Rather than breaking down over a few years, remains in these conditions can stay recognizable for decades and may take 50 or more years to fully skeletonize.
How Royal Coffins Are Built
Royal coffins follow a centuries-old design: an outer shell of English oak with a complete lead casket fitted inside. The lead creates an airtight, moisture-proof inner chamber around the body. Queen Elizabeth II’s coffin, made roughly 30 years before her death from English oak sourced from the Sandringham estate, weighed an estimated 550 to 700 pounds. Princess Diana’s lead-lined coffin weighed nearly 540 pounds. The enormous weight comes almost entirely from the lead lining itself, with brass fittings and ceremonial hardware adding to the total.
English oak is now so scarce and expensive that modern coffins typically use American oak instead. Andrew Leverton, whose family firm maintained the late Queen’s coffin, noted that sourcing English oak for a coffin today would be essentially impractical. The coffins are built well in advance and stored, sometimes for decades, until they are needed. Specialist funeral directors handle both the original construction and ongoing maintenance of the casket over the years.
Embalming Before the Vault
Modern royals are embalmed shortly after death. Preservative fluids are injected throughout the body to delay bacterial breakdown, a process that likely begins within hours. For Queen Elizabeth II, embalmers used every available technique to ensure her body could lie in state for roughly ten days without visible deterioration. Cooling devices were also believed to have been placed beneath or inside the casket during the lying-in-state period.
Not every monarch has been embalmed. Queen Victoria famously refused the procedure. Her father-figure predecessor in modern practice, George VI, was embalmed, and the process has been standard for royals since the 20th century. The combination of professional embalming followed by a sealed lead coffin provides two layers of preservation: the chemical treatment slows bacterial activity from inside, while the lead seal blocks moisture, insects, and oxygen from outside.
What Happens Inside a Sealed Lead Coffin
Once the lead-lined coffin is sealed, the body enters a very different decomposition path than it would in an ordinary grave. Without oxygen, the aerobic bacteria that normally drive rapid decay cannot function. Insects, which are responsible for much of the breakdown in open-ground burials, are completely excluded. This is why lead lining can preserve a body in recognizable condition for up to a year or longer, even without embalming.
Decomposition doesn’t stop entirely, though. Anaerobic bacteria, the kind that thrive without oxygen, continue working at a slower pace. These organisms gradually break down soft tissue, producing gases and fluids that remain trapped inside the sealed casket. In a sealed metal environment combined with embalming, complete skeletonization typically takes between 25 and 50 years, with some estimates stretching beyond 50 years depending on conditions. The sealed environment that keeps external elements out also traps decomposition byproducts inside, which can actually create conditions favorable to certain anaerobic bacteria over time.
The practical result is that a body in the Royal Vault exists in a kind of extremely slow decline. For the first several years, remains are likely well preserved. Over the following decades, soft tissue gradually breaks down in the oxygen-free darkness of the lead casket. After half a century or more, skeletal remains are what typically survive.
The Royal Vault Itself
The Royal Vault sits beneath St George’s Chapel at Windsor Castle, accessed through an opening in the stone floor of the chapel. Coffins are lowered into the vault during funeral services. The space holds the remains of numerous monarchs, consorts, and other members of the royal family, some dating back centuries. Elizabeth I and Charles II were both buried in lead-lined coffins, as were notable figures like George Frederic Handel and Sir Francis Drake in other locations following the same tradition.
The vault functions as both a permanent and temporary resting place depending on the individual. Prince Philip’s coffin was initially placed in the Royal Vault after his funeral in April 2021 but was later moved to the King George VI Memorial Chapel, a smaller side chapel within St George’s, to join Queen Elizabeth II. George VI, the Queen Mother, and Princess Margaret’s ashes are also in that memorial chapel. Other royals remain in the main vault permanently, their lead-sealed coffins resting in the cool, dry stone chamber indefinitely.
Why Lead Lining Became Tradition
The practice of sealing royal remains in lead dates back centuries in England. The logic was practical: royals are often interred above ground in vaults and chapels rather than buried in earth. Without soil, insects, and natural drainage to manage decomposition, an unsealed coffin in a stone vault would eventually leak fluids and produce powerful odors in a space where services are regularly held. Lead solves this by creating a permanently sealed container that keeps everything contained.
The tradition also reflects the reality that royal remains may need to be moved. Prince Philip’s transfer from the Royal Vault to the Memorial Chapel is a recent example, but coffins have been relocated throughout history for renovations, new memorial construction, or changes in dynastic arrangements. A sealed lead coffin makes this possible without the problems that would come with moving a deteriorating wooden casket. The weight is a significant trade-off: it took eight soldiers from the Grenadier Guards to carry the Queen’s coffin, and pallbearers at royal funerals are selected partly for physical strength. But the preservation benefits have kept the tradition alive for hundreds of years.