Each year the International Day of Peace is observed around the world on 21 September. The day was established in 1981 by the United Nations General Assembly and in 2001, the General Assembly voted to designate the day as a period of non-violence and ceasefire.

To mark the day, here's 17 famous quotes about peace.

1. "Peace is a daily, a weekly, a monthly process, gradually changing opinions, slowly eroding old barriers, quietly building new structures."  - John F. Kennedy

2. "If you want to make peace with your enemy, you have to work with your enemy. Then he becomes your partner." - Nelson Mandela

3. "Peace cannot be kept by force; it can only be achieved by understanding."  - Albert Einstein

Former South African President Nelson Mandela

Former South African President Nelson Mandela

4. "Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." - Martin Luther King, Jr.

5. "If the human race wishes to have a prolonged and indefinite period of material prosperity, they have only got to behave in a peaceful and helpful way toward one another." - Winston Churchill

6. "There is a higher court than courts of justice, and that is the court of conscience. It supersedes all other courts." - Mahatma Gandhi

Winston Churchill making the victory sign.

Winston Churchill making the victory sign.

7. "Peace comes from within. Do not seek it without." - Buddha

8. "If we have no peace, it is because we have forgotten that we belong to each other." - Mother Teresa

9. "We look forward to the time when the Power of Love will replace the Love of Power. Then will our world know the blessings of peace." - William Ewart Gladstone

Mother Teresa at the Home for the Dying in 1980

Mother Teresa at the Home for the Dying in 1980

10. "Imagine all the people living life in peace. You may say I'm a dreamer, but I'm not the only one. I hope someday you'll join us, and the world will be as one" - John Lennon 

11. "I believe in the religion of Islam. I believe in Allah and peace" - Muhammad Ali 

12. "If you want peace, you don't talk to your friends. You talk to your enemies." - Desmond Tutu 

Muhammad Ali during a training session in Munich, Germany in 1976

Muhammad Ali during a training session in Munich, Germany in 1976

13. "An eye for an eye only ends up making the whole world blind." - Mahatma Gandhi 

14. "Democracy is necessary to peace and to undermining the forces of terrorism." - Benazir Bhutto 

15. "Peace begins with a smile." - Mother Teresa 

Ban Ki-moon at UN Peace Day event in New York

Ban Ki-moon at UN Peace Day event in New York

16. "Do you know what astonished me most in the world? The inability of force to create anything. In the long run the sword is always beaten by the spirit. Soldiers usually win battles and generals get the credit for them. You must not fight too often with one enemy, or you will teach him all your art of war. If they want peace, nations should avoid the pin-pricks that precede cannon shots." - Napoleon Bonaparte 

17. "It isn’t enough to talk about peace. One must believe in it. And it isn’t enough to believe in it. One must work at it." - Eleanor Roosevelt

Source: The Telegraph