Heat the olive oil in a large saucepan. Sauté the onion, garlic and chillies at a low temperature for about 6 minutes until the onion is translucent. Add the anchovies and stir in well.
Add tomatoes, oregano, olives and capers. Bring to a boil. Reduce the heat, season and simmer.
In the meantime, cook the pasta in a large saucepan with salted boiling water until al dente.