ST. PETERSBURG, Russia — Maria Ryadova recalled being in a dusty room inside the Alexander Palace, hopping from one floor beam to another and peering into the dark chasm beneath, on the day she and her team of workers made a momentous discovery.

A pile of broken blue tiles had been hiding in the darkness. These shards, Ms. Ryadova knew from archival black-and-white photos, were the remains of tiles that had once adorned the walls of that room, which used to be czar Nicholas II’s private pool and bathroom in the early 1900s. But before they were uncovered, she had never known their color.

The discovery of these glossy pieces of cobalt and turquoise completed another piece of the puzzle that has been reconstructing this imperial mansion, which was once the home of the last czar of Russia and his family.

“This was an incredible find,” said Ms. Ryadova, 40, who is one of the main architects involved in the project. “I felt extremely inspired.”

With a team of architects and researchers, Ms. Ryadova has spent more than a decade on these grounds, working to restore the stately yellow edifice to its early-20th-century glory, before World War II and Soviet remodeling led to its deterioration. On Aug. 13, the work of Ms. Ryadova and many others was finally unveiled when Alexander Palace opened to the public as a museum.

This palace will likely be the final major Russian imperial mansion to become a museum, said Tatiana Andreeva, a research specialist. It is the result of years of investigative work by Ms. Andreeva, 37, Ms. Ryadova and their many colleagues, who re-created the interiors by working with a few fuzzy colored pictures, thousands of black-and-white photos, some watercolors, several drapery swatches and memoirs of palace life.

Of Rubble and Rubles

More than a century after the Russian monarchy collapsed with the execution of Nicholas II and his wife, four daughters and son by the Bolsheviks in 1918, historians are working to excavate the country’s imperial past.

For some, Alexander Palace has become a symbol of Russia’s reconciliation with it. “I have a complicated attitude toward the aristocrats of pre-Soviet Russia,” said Max Trudolyubov, 51, a popular blogger and commentator on current affairs. “But these palaces became monuments.”

Nicholas II has long been portrayed to the Russian people either as a bloody and committed despot — a relentless oppressor of the working class — or a clueless and lighthearted fool who carelessly let his country fall of the cliff into the abyss of Bolshevism.

The reopened palace will allow visitors to immerse themselves in part of the country’s history and make their own judgments, said Lev Lurie, a specialist in the history of St. Petersburg and the Romanov family.

“Museum is a theater, with a play rolling out without any actors,” she said.

In 2011, the Russian state decided to recreate the czar’s private suite — which had been furnished in the Art Nouveau style and was mostly destroyed during World War II and subsequent Soviet reconstructions — and create a museum around it. In the end, the government has committed more than $28 million to the project, with $12 million coming from the museum and private benefactors. (One of those private benefactors, Bob Atchinson of Austin, Texas, is an enthusiast who has assembled a collection of items that were looted from the palace by the Germans and others — and sold at international auctions — and who has been collecting money to repair the palace for decades.)

To recreate the czar’s private rooms, Ms. Ryadova’s team had to remake almost everything: pickled oak parquet floors, wool rugs and silk draperies, and even spittoons that were used by the imperial family and courtiers.

Originally built in 1796 by Catherine the Great for her grandson Alexander, the palace was part of the imperial retreat in Tsarskoye Selo, a sprawling complex of palaces and parks outside of St. Petersburg, Russia’s capital at the time.

In 1905, Alexander’s great-grand-nephew, Nicholas II, moved his family there permanently to escape the increasingly chaotic and dangerous life in the capital, where riots broke out regularly and his grandfather was killed in 1881.

Nicholas II’s choice, on the eve of revolution, to abandon his troops and reunite with his family at Alexander Palace, divides many who study the time period.

To some, it is an indictment: He put his family above the interests of his country, over which he had absolute power.

But to many Russian Orthodox believers, Nicholas II’s acceptance of his fate was a show of humility. In 2000, the Russian Orthodox Church canonized him and his family as passion bearers, a category used to identify believers who endured suffering and death with Christ-like piety.

This July, defying all pandemic-related restrictions, thousands of believers joined a religious procession in the city of Yekaterinburg that processed from the location of the mansion where the czar was shot (it was later destroyed) to the spot where the family’s remains were disposed in a mine shaft and dissolved with sulfuric acid.

A Palatial Puzzle

As she walked through the palace’s nearly finished rooms a few weeks before the opening this summer, Ms. Ryadova said she hoped visitors would be enraptured. She has faced too many challenges and disappointments in this reconstruction to feel otherwise.

For instance, she has been frustrated by the czar’s family photos. As avid photographers, they took thousands of pictures inside the palace, including photographs that could be considered some of the world’s earliest selfies. Portraits, however, are often useless to restoration specialists because floors and ceilings are usually cut out of the frame.

“Now I tell everyone: Photograph your ceilings!” Ms. Ryadova said.

Rugs posed a problem, too: In some cases, whole patterns were recreated from a small corner that managed to sneak into a picture or two. (Some of the ceiling restorations are on hold, in hopes that more materials will be discovered.)

In 1944, after the German occupation, most of the properties at Tsarskoye Selo had no windows or roofs. “The country was in a horrible state, but people wanted to see these ruins rebuilt as they were,” said Olga Taratynova, the director of the Tsarskoye Selo museum.

So even though the Soviet government had established itself as antithetical to the rule of the czars, it put money toward renovating their palaces. “It was a political decision,” Ms. Taratynova, 66, said.

The complex has since become an important tourist destination, not to mention a symbol of Russian history. Ms. Taratynova recalled that in 2002 President George W. Bush visited the Catherine Palace at the site as the guest of President Vladimir Putin. When Mr. Bush entered the grand 8,500-square-foot throne hall, with its gold-plated woodcarving décor, Ms. Taratynova said, he froze, mesmerized, and said simply, “Wow.”

“We Russians love it when people come to visit and say, ‘Wow!’” she said.