It is also the first cryptocurrency to use proof-of-stake technology, an energy efficient solution to securing its network, which was invented by Peercoin's architect, Sunny King.
Not true. PoS was invented much earlier
https://bitcointalk.org/index.php?topic=27787.0 . Sunny King though was the first to implement it.
Proof-of-stake was invented by Sunny King and Scott Nadal independent of what was going on at BitcoinTalk. Check this interview...
http://letstalkbitcoin.com/blog/post/the-real-sunnySM: What led to the creation of the proof-of-stake algorithm? What inspired you? Do you remember where you were or what you were doing when you came up with it?
SK: That was in 2011, we had a small study group on bitcoin
Back then there were already a few 'altcoins' floating around, and more being created, but of course not as much as nowadays. We were thinking about something different, not a clone of bitcoin, but different algorithms, for example, addressing the energy problem of bitcoin.
That's how we started looking into alternative consensus mechanism, that using coins itself to secure cryptocurrency. We came up with the ideas ourselves, but later we learned that some people were discussing related ideas on bitcointalk forums in 2011 as well. Overall I think proof-of-stake is a good term describing the general ideas. The difference is, in 2011 we were pretty much the only people committed to use pure proof-of-stake as consensus mechanism. Everyone else were just trying to see if proof-of-stake can provide some patchwork to bitcoin's proof-of-work.