Here are some places that are important in my world, given historically.
About 410 years ago, dwarves from a faraway kingdom began to expand into these islands. They set up two colonies, one mining quality iron on Homb Island (Grolo Grotto), and the other, the Mines of Dunharrow, mining rare ores on Kaufle Island. Somehow, this expansion riled up someone and the decision to do something went all the way up the ladder. Surma and the Horde organized all the nearby races and in a well-organized surprise initial attack and campaign, utterly destroyed that kingdom and all it's towns, colonies, etc. Only one survived.
Seker and the Heroes learned of the attacks too late to stop the war, but saved one small town and set in motion a plan to allow it to grow and even thrive. The armada sent to destroy the small colony of Grolo Grotto was destroyed by a storm, but a few individuals were allowed to swim to safety. Their memories were modified so they remembered destroying Grolo Grotto, and the storm arising as they were heading home. The Horde went home, thinking the job was finished. Meanwhile, about 100 humans were sent through a gate to arrive in the Temple to Ukko in Grolo Grotto to join the 200 or so dwarves there. At that point, the whole group of islands was magically barricaded from the rest of the world. This is now referred to as the first year of our survival, or just Y 1.
The human/dwarven civilization remained hidden for about 50 years, growing in secret and protected by "neutral" creatures. From that point the population had grown enough and the expansion began. North and east they expanded, usually by slow attrition rather than major battles, but major battles were fought for the Vaulted Caverns (Y114), near Safe Harbor (Y143), and the final and largest battle in the northeast, in the area of the great Temple of Marog (Y 185). With Homb Island now under control, expansion stopped for awhile and society grew. The population boomed and the standard of living improved. Culture and literacy went from that of a frontier outpost to a thriving society. A group of druids settled the western isles and set up their great temple in Aspen Grove in Y 256. Humans improved their seamanship and began to fish and rule the seas. Many small islands were also settled without much resistance.
A second wave of expansion began with the first outpost planted on another island in Y324, the 200th anniversary of the taking of the Vaulted Caverns. A group of mostly dwarves built a fort on Southern Tobian named Granite Knoll. The ruling council in Safe Harbor declared that any who could claim and settle such an area would earn an equal place on the council. More colonies were quickly planted on all the surrounding isles. Most were abandoned or wiped out within a few years. Larger, more organized efforts were made with more money and manpower, and now six such colonies are well established with large supporting populations. As the population on Homb continues to grow, a steady supply of settlers flow outward to the free land and opportunity of the frontier towns.
It is now the year 385.
Grolo Grotto: Founded in -8Y. The first dwarven colony on these islands. It is still the largest dwarven city and produces excellent iron products. It also has a large temple to Ukko and is a center of history and cultural learning.
Sunrise Shore: Founded in Y105, it's a smaller town, it is mostly made up of human herders and fishermen.
Vaulted Caverns: Captured in Y114, it is a major town, crossroads and central market, consisting of a large system of caverns inhabited mostly by dwarves and an outdoor area for humans. The great school of Vainamoinen and the Bards is here. It is also a port city and fishery.
Safe Harbor: Founded in Y145, Safe Harbor has become the capital and port city and home of the ruling council. It sits on a wide flat area very good for agriculture. Most of the inhabitants are human, and the whole area has become populated and cultivated. A large guild of mages and sorcerers is here, as well as large temples to Ukko and Seker.
Gentle Hills: Founded last of the dukedoms on Homb in Y186, this region is less populated. The hilly area is home to sheepherders and orchard growers. The capital city is the only decent natural port in this region. The great Temple to Ilmatar is here.
Aspen Heights: Cleared of orcs and founded by the followers of Meilikki in 256, Aspen Heights rules over the Western Isles. Many isles here are still undeveloped, and the villages that exist are mostly populated by fishermen/sailors. The best timber and largest shipbuilding site is here, as well as the impressive Aspen Grove holy site.
Sylvan Glade: The oldest surviving frontier town (Y332), it's made from a mixture of all types of hardy woodsmen and warriors. The only temple to Kullervo is found here.
Gont: Too small to merit a dukedom, the island of Gont is known for it's school of combat, training warriors, paladins, monks, and rangers, as well as its master smiths. The whole island is involved in supporting the school. It was settled in Y 334.
Fertile Valley: was settled next in Y341 by a group of powerful adventurers. The current Duke Mardour's father won the random draw to become duke, and to dedicate the town to his class. A quality Ranger-archer school is found here. Most of the land is suitable for agriculture and it has grown faster than most of the frontier towns.
Obsidian Halls: is a mostly dwarven town located in some beautiful caverns carved from the rock and obsidian. Founded in Y 349, it is an steady source of rubies among other things. Quality fighters and paladins are trained here as well.
Oak Glen: This town, founded in Y 350, is probably the most dangerous of the frontier towns. Farmers are few. Many of the inhabitants still adventure here, and schools and temples of all classes are here, though the magic guild and ranger school are reknown.
Silk Island: This dukedom is small, and was made a dukedom due to it's economic power. The duke carefully controls the secret of silk and his monopoly over all it's uses. Visiting is not encouraged.
Maple Hills: was founded by the next generation of the same familes as founded Fertile Valley in Y369. This time the wizard won the draw and was named duke. A decent guild has been started here.
Victory Heights: founded in Y376, is an expansion from Sylvan Glade as a gift to the duke's in-laws for their lavish support after a major battle. A fledgling magic guild and a decent temple to Ukko can be found here.