The Vatican never purchased it.
It was erected before Christ, possibly in the time of Emperor Octavian and stood in the same place for 1600 years.
It was presumed to be the obelisk before which Nero, Diocletian, etc. presided over the torture of Christians. At some point in the ancient past it was graffitoed with the defiant Christian motto Campion related to us.
It was considered as a reminder of the dark days before Constantine for centuries.
In 1586 it was relocated to the Piazza to remind the congregants of the triumphant St. Peter's Basilica that their faith had humble beginnings in the torture and martyrdom of their ancestors.
This symbolism was remarked upon at the time in public speeches - not 250 years after the relocation.
You've been caught in another lie.
Sorry. Upon further review you are correct. It was not my intention to lie.
It was one of the very same Egyptian obelisks that stood in Egypt in Heliopolis in ancient times when the myster religion came to pagan Rome. It was hauled there at great expense. Pope Sixtus V ordered it to be moved a little in 1586 in order to centre it in front of St. Peters. Elohim ordered these to be destroyed in the OT. Instead it sits in front of St. Peters'. A silly reminder of pagan persecution. It should be destroyed.