IN HŌC SIGNŌ VINCĒ

The Chi-Rho (☧) is one of the oldest and most powerful symbols in history, formed by overlaying the first two letters of the word "Christ" in Greek: Chi (X) and Rho (P).

In 312 AD, before the pivotal Battle of the Milvian Bridge, Roman Emperor Constantine claimed to see a vision in the sky showing this symbol alongside the words In hoc signo vince. He painted it on his soldiers' shields, won the battle, and subsequently legalized Christianity across the Roman Empire