Trenitalia's ETR1000 is the 1st very high speed train, which is certified according to the TSI. The design of its running gear was derived from the BOMBARDIER ZEFIRO 380'*. Some of the essential challenges during homologation of the bogies are described. The major topics have been the proceeding of the calculations, tests and proofs, and this especially for the wheelsets and the structural parts. Moreover, the running dynamics and, closely linked to this, the mechatronic subsystems in the bogie provided a wide working field. The complexity of cooperation with authorities, assessors, test institutes, subsuppliers etc. can only briefly be mentioned. A selection of results may illustrate some of the aspects mentioned before. The successful finalization of all acceptance activities allows the start of commercial operation in June 2015. Due to the size, this paper will be published in two separate parts. Part 1 was mainly dedicated to the homologation procedure and structural mechanics, and part 2 is focused on vehicle dynamics, mechatronics and further topics. [ABSTRACT FROM AUTHOR]