Indonesia is a chain of islands, an archipelago, running between the Pacific and the Indian Oceans. Some of the islands are tiny, too small to live on. Others are huge, among the biggest in the world. Indonesia includes nearly 6000 inhabited islands, stretching 5000 kilometres from east to west. The people living on the different islands speak different languages, follow different religions and wear different sorts of clothes. Altogether, they make up the fourth largest population in the world.

The islands of Indonesia curve along the Equator, and it's hot all year round. But there are still seasons in the calendar. From June to September the monsoon, or seasonal wind, is from the east. This makes the weather fairly dry. From December to March the monsoon blows from the west. This wind is wetter, so it rains more often, sometimes very heavily.

Some of Indonesia's islands have been formed from volcanoes. Some of the volcanoes are old and worn down. Others are new and still dangerous, throwing out hot rocks, ash and gas when they erupt. But eruptions bring up fresh minerals from deep in the Earth that make the land very good for farming. The Indonesian islands of Java and Bali have always had high populations, because of the fertile soil and regular rainfall.

If you climb the Indonesian mountains of Kalimantan or Irian Jaya, you'll fight through thick rainforest until it's too high even for trees to grow. By contrast, the islands of the south-east seem bare, with grassy plains that are dry for much of the year. The sea is an important part of Indonesia, too. Beautiful coral reefs fringe many of the islands. In fact Indonesia covers more water than land.

Hundreds of thousands of years ago, when northern Europe was still covered by ice, there were already people living on Java using fire and tools. Today's Indonesians have ancestors from as far away as Melanesia, southern China and Vietnam. Java and Sumatra first developed under Malay and Indian influences.

Indian culture brought writing, the potter's wheel, and textile dyeing. It also brought new religions, Hinduism and Buddhism. Indonesian puppet and dance plays still tell stories from the Hindu legends. Buddhism and Hinduism appealed to the ruling classes. But when the new faith of Islam reached ordinary people, with the important idea that we are all equal in the eyes of God, it was very popular. Today there are more Muslims living in Indonesia than in any other single country. People of all these different religions still live by adat, the traditional Indonesian laws of social behaviour.

Muslim traders were attracted by the precious woods and spices that grow in Indonesia. And when pepper, cloves, cinnamon and nutmeg were sent to Europe, merchants there soon set sail to find the famous 'Spice Islands' for themselves. Traders from all over Europe fought for control of the islands, but in 1602 the Dutch East India Company put themselves in charge and made the 'East Indies' a colony. By the nineteenth century, people were forced to grow crops like coffee and rubber for the Dutch, instead of food to eat. They often went hungry. After the second World War and their own bitter fight, the people finally won Independence and formed the new country of Indonesia. With 250 languages in the archipelago, they needed to pick one in common and Bahasa Indonesian became the official language.

The first government made many plans to help the people. But in 1965 there was a violent change of power, when many people were killed. When the Dutch and Portuguese finally left the nearby colonies of West Papua and East Timor, the Indonesian government took them over (and re-named West Papua 'Irian Jaya' But for many of the people in these territories, Indonesia is like another foreign country. Altogether, millions of people people live in Indonesia, but they're not evenly spread. Although the island of lava has only seven per cent of the land area, sixty per cent of the people live there. Imagine over 100 million people living on an island just over half the size of Britain! Such a dense population puts great pressure on the environment.

The government has tried moving people from Java to other islands where fewer people live. But this causes tension because local people feel their way of life is being threatened. And the migrants themselves can't always live as they would have back in Java. Their way of farming is often not suitable for the thinner soil on other islands. City life and country life. Millions of people are still moving to the island of Java every year. Almost all of Indonesia's new industry is based here and the capital city, Jakarta, is the centre of government and business power.