Blazon: Gules a cross patriarchal paté argent surmounted by a triple mount in base azure
Twenty-seven years ago marked the establishment of the modern Slovak Republic, which makes today the :checks notes: Day of the Establishment of the Slovak Republic, so let’s take at their arms! If you think they look awfully similar to the arms of Hungary moderne (on the sinister), you are absolutely correct! The cross patriarchal was a symbol of Stephen I, King of Hungary; his territory included both present-day Hungary and present-day Slovakia. His reign began around 1000, so it’s been in use for a while. The Árpáds, the ruling dynasty of Hungary, continued to use the cross patriarchal on and off for the rest of their tenure (sometimes alternating with Hungary ancien, which was barry of eight gules and argent). By the time the Habsburgs took control of the area in 1526, the cross patriarchal was pretty firmly associated with both territories.
The triple mount was first used around the turn of the fourteenth century by Wenceslaus III, who still ruled both Hungary and Slovakia. It was green (like the Hungarian arms) for a very long time, but in 1848, the Slovak National Council changed it to blue to fit with the pan-Slavic color scheme. This created the Slovakian coat of arms as it exists today. (Yes, it does violate the law of tincture, but the patriotic energy of 1848 really didn’t have time for such antiquated nuances – and yes, I did fudge the blazon a bit so the violation is less obvious.)
There were a few interruptions in the use of these arms since 1848, the first of which occurred upon the establishment of the Slovak Soviet Republic in 1919, which used a molet of five points gules. In 1920, Slovakia was incorporated into Czechoslovakia and no longer used its own arms.
When the First Slovak Republic was established in 1939, they went back to the prior arms, but they were banned starting in 1960 as a symbol of fascism. They were replaced by a Soviet heraldic design that holds the dubious distinction of being possibly the least hideous example of the genre. After the Velvet Revolution and the dissolution of Czechoslovakia three years later, though, the old cross patriarchal and triple mount returned.