1) The Battle of Waterloo in 1815 marked the final defeat of Napoleon Bonaparte and the end of his reign as Emperor of France.

2) The development of blockchain technology, first introduced in 2008 with the creation of Bitcoin, has enabled secure and decentralized digital transactions and led to the emergence of cryptocurrencies.

3) The Great Barrier Reef in Australia is the largest living structure on Earth and can be seen from space.

4) Priyanka Chopra Jonas is an Indian actress, singer, and film producer who has made significant contributions to both Bollywood and Hollywood. She gained international fame through her role in the television series "Quantico" and has since starred in successful films.