Durham Castle marketplace!--which he refused on January 4, 1570. With the sanction of Pope Gregory XII, the Blessed Thomas was represented on the walls of the ancient church of the English College in Rome and Pope Leo XIII declared him a martyr and beatified him in 1886 among a group of 54. The Catholic Church of St. Cuthbert in Durham mentions him in the history of their church and the Hexham and Newcastle Diocese lists him among the Northern Saints and Martyrs, celebrating a diocesan feast on July 25. Note that the crucial issue for his being declared a martyr is that he was given a chance to save his life by renouncing his faith and refused it.
For more information about the Northern Rebellion, see my review of a study of the rebellion.