1. Talingarde is an island that's rather isolated from the rest of the world. It's temperate in the southern regions, but the north of the island is quite cold and often blanketed with snow. Most people avoid the north due to the large amount of dangerous monsters.
2. Talingarde is a lawful good nation - a place of law and order. Violations of the law are punished severely but fairly. The people also revere the ideals of goodness. Clerics tend to the sick, often for no pay. Knight seek to protect the weak. Paladins are often featured in stories and songs. In all of Golarion, Talingarde is likely the most committed to the ideals of law and good.
3. Talingarde is a monarchy ruled by good king Markadian V (called the Brave). He's a much-beloved ruler from a well-established royal family known as the House of Darius.
4. The King has no son, so his heir is the beautiful princess Bellinda. Still unmarried at the age of 20, she's the only other full-blooded member of the royal family. The King's wife Lucinda died in childbirth, and he has never remarried.
5. Markadian V is actually the great grandson of Markadian I (called the Victor) who established the House of Darius after defeating the former royal house (the House of Barca) at the Battle of Tamberlyn. Even decades after his death, the Victor is still beloved by the people, and statues of him are everywhere.
6. Other deities used to be worshiped, but this came to an end under the House of Darius. Now, Talingarde is a monotheistic nation. Worship of Asmodeus is punishable by death by burning. Worshiping other non-evil deities is technically allowed but highly discouraged and rarely seen. Almost 100% of the population worships Mitra.
7. Mitra is the god of light, healing, goodness, and leadership. He's usually depicted as having three aspects: a king, a healer, or a living flame.
8. Every town in Talingarde - no matter how small - has at least one church of Mitra. His priests are almost always important community leaders. The second most-powerful man in the kingdom is High Cardinal Vitallian of Estylls. The word of the clergy is not law, but it is always heard and respected, and ignored only infrequently. The Mitran Church and the House of Darius are strong allies, fiercely dedicated to keeping Talingarde a bastion of goodness, law, and Mitran devotion.
9. Asmodeus used to be part of the pantheon of Talingarde. He was not loved, but feared and respected. Twenty years ago, Markadian IV (called the Zealot) outlawed the faith and unleashed the Inquisition against it. In the Purges, every Asmodean temple and priest was burned. Now, his worship is punishable by death.
10. Talingarde is defended by the Knights of the Alerion - a legendary order of warriors who uphold the right, protect the weak, and work to see justice done. They're a religious order, and every member has sworn oaths to Mitra. Anyone (even the lowest of commoners) can become a knight if they are deemed worthy. Not all Knights are Paladins, but the order has produced more Paladins than any other.
11. Talingarde has six regions. The Cambrian Ports are the three large cities that sit upon the Bay of Cambria. The Heartland is the farms and rural regions. The Borderlands are the northern reaches of the kingdom, protected by the Watch Wall. The Cae Bryr is a great forest inhabited by the savage Iraen. The Savage North is a wasteland of ice ruled by monsters. The Lands of the Yutak are scattered small northern islands inhabited by tribes of strange nomads and fishermen.
12. The northern border of Talingarde is protected by 12 fortresses collectively known as the Watch Wall. They control every point of access from the Savage North and defend the land from bugbear incursions and other monster attacks. Markadian V earned the title "Brave" while defending the Watch Wall.