in the old Lombardic style. The old flat chancel end on the east side was replaced with a large apse, which external gallery with a narrow arcade supported by short columns crowned the semicircular wall with a wide pseudo arcade and tall pilasters on both sides. The new chancel had a triple-nave crypt. The damaged square tower had been replaced with an octagonal dome, above which an octagonal tower was added later. Flanking stair turrets remained from the first cathedral. These changes closely resembled the renovations Henry had overseen on Speyer Cathedral a few years earlier. Henry also undertook a few other minor changes, such as raising the transept on the east side and adding openings at the column level. These column-level portals were among the first ever such constructed. Henry died in 1106, before his intended changes were complete. With his death, the funding for the renovation of the cathedral dried up and so the remaining construction was abandoned. Mainz Cathedral is considered one of the three Kaiserdome ("Emperor's Cathedrals") of the Holy Roman (German) Empire, along with Worms Cathedral and Speyer Cathedral. Evolution of the main nave Archbishop Adalbert I of Saarbrücken (1110–1137) had a two-story chapel, called the Gotthard Chapel, built as the official palace chapel next to the cathedral. It is believed that he also ordered the renovation of the main body of the cathedral, mainly due to similarities between the main hall and the vault of the new chapel. Conception for the renovations was again taken from the Romanesque Speyer Cathedral. This time, however, without money from the emperor, the builders lacked the resources to acquire the high-quality sandstone used in Henry's additions. They instead used limestone. The other aspects of the renovations were also much cheaper, and the extravagant style of Speyer Cathedral was largely avoided. The central nave was built to an impressive 28 meters, five meters short of Speyer Cathedral's 33. It seems that the blind arches were intended to encompass the windows, as in Speyer Cathedral, but the height of the roof did not allow this. The resulting three-level effect, due to the arches ending before the windows, was a technique not before seen in architecture. The main hall was further renovated throughout the entire 12th century. The entire outer wall structure was eventually replaced. Around the year 1200, the ceiling was replaced with a ribbed vault, a rather new technique