The oldest part of the complex is the Ivan the Great Bell Tower, built where the bell tower of a 14th century church once stood. The architect who had it built in 1505-1508 was an Italian, Marco Bono. Initially it was about sixty meters high, with an octagonal base, topped with a dome. A few decades later it was raised to its current height of 81 meters and for a long time was the highest construction in all of Moscow, since it was forbidden to construct buildings higher than it.
