On the morning of , a group of officers commanding about 3,000 men (elements of Life-Guards Moscow Regiment, Grenadier Life Guards Regiment, and Naval Equipage of the Guard) assembled in Senate Square, where they refused to swear allegiance to the new tsar, Nicholas I, proclaiming instead their loyalty to Constantine. They expected to be joined by the rest of the troops stationed in Saint Petersburg, but they were disappointed. The revolt was hampered when it was deserted by its supposed leader Prince Trubetskoy. His second-in-command, Colonel Bulatov, also vanished from the scene. After a hurried consultation, the rebels appointed Prince Eugene Obolensky as a replacement leader.