Colchester Hospital University NHS Foundation Trust must tackle concerns over the quality and safety of patient care, the health service regulator has said.
Monitor said the trust was put in special measures "to ensure all its patients receive good quality care".
A formal investigation found the trust had breached its licence to provide health services.
The trust will be required to "put right the patient quality, safety and governance concerns highlighted by the CQC" under the measures, Monitor said.
The hospital will also be matched with a high-performing trust which can offer support and expertise, and an improvement director will also be appointed to ensure their are effective changes.
More top news
With the government ordering tests on the Hotpoint in which the Grenfell Tower fire started, here's how you can check your fridge freezer.
The Duke of Edinburgh has cancelled an appearance at a London Zoo event as he continues to recover from an infection.
The court heard how two-year-old Jeremiah Regis-Ngaujah suffered more than 100 separate injuries, including an adult bite mark on his chest.