Answer:
By foundation he meant the reason of the Britishers to rule India.
Step-by-step explanation:
One of the most famous acts of protest of freedom fighter Gandhi began on March 12, 1930. The day when he launched a protest against the Salt Acts, which forbade Indians to gather, produce, or sell their own salt, and thus require them to purchase it from the British masters.
This act shook the foundation of the British Empire because after he was jailed for seven months for this act his example was followed by thousands of Indians, continuing to make salt on the seashore and taking to beating and arresting. It led to a wave of gaining freedom by peaceful means among the common masses.