Answer:

1. They established their trading centres in different parts of the country, especially in the coastal areas. These centres were called 'factories'. It was so because the officials of the company were called 'factors'. Factories were base of company traders known at that time as factors operated.
2. It was considered an important landmark beacuse it was the first major victory of the britishers. It was fought between Siraj-ud-Daula and the Britishers in the year 1757.It is considered important landmark in history of India because it made the British a souverign power in India.