In the meantime, the siege of Smolensk continued, even as Władysław was named tsar of Russia and cities and forts throughout the area swore allegiance to the Poles. However, Sigismund III required that Smolensk not only swear allegiance, but open its gates to the Poles, which the Russians refused to do. Żółkiewski fortified Moscow with his army and returned to King Sigismund III, who had remained at Smolensk while Żółkiewski negotiated in Moscow. The largest tunneling project at Smolensk came in December 1610; however, the Poles only managed to destroy more of the outer wall – the inner wall remained intact. The siege continued. At one point, the Polish guns breached the outer wall, and the governor of Braclaw (Bracław) ordered his soldiers to rush in; however, the Russians had predicted where the breach would occur and had fortified that part of the wall with additional men. Both sets of troops were slaughtered, and the Poles were eventually beaten back.