Under the heel of somebody
Definition 1 of 1
Pro Tip 1/3Power Imbalance
Use when showing that one person or group has much more power over another. 
After the merger, employees felt they were under the heel of the new management.
Pro Tip 2/3Negative Connotation
Has a negative feeling, suggesting abuse of power or unfair treatment. 
The tenants were under the heel of the landlord who would never repair anything.
Pro Tip 3/3Metaphorical Use
It's metaphorical, there's no literal heel or control, but rather a feeling of being dominated. 
The artists felt they were under the heel of the censor board.