The 3rd century is the period from  201 -  300 in accordance with the  Julian calendar in the Christian Era.
       
 Overview
      
 Events
      
       
          The Baths of Caracalla, in 2003
 
        
       
      
       - 212:  Constitutio Antoniniana grants citizenship to all free Roman men
 - 212-216:  Baths of Caracalla
 - 230-232:  Sassanid dynasty of Persia launches a war to reconquer lost lands in the Roman east
 - 235-284:  Crisis of the Third Century shakes Roman Empire
 - 250-538:  Kofun era, the first part of the  Yamato period in Japan
 - 258:  Valerian's Massacre of Christians
 - 260: Roman  Emperor Valerian I is taken captive by  Shapur I of Persia
 - 184-280: Period of the  Three Kingdoms
 - 280-420:  Jin Dynasty (265-420) of China
 -  Sarnath becomes a centre of Buddhist arts in India
 - Diffusion of maize as a food crop from Mexico into North America begins
 - The Kingdom of  Funan reaches its zenith under the rule of  Fan Shih-man
 - The  Goths move from  Gothiscandza to Ukraine and shape the  Chernyakhov culture
 
      
 Significant persons
      
       -  Clement of Alexandria
 -  Diocletian, Roman emperor
 -  Diophantus of Alexandria, wrote Arithmetica
 -  Hippolytus, considered first  Antipope
 -  Liu Hui, Chinese mathematician
 -  Mani (prophet), founder of  Manichaeism
 -  Origen
 -  Pappus of Alexandria, Greek mathematician
 -  Plotinus, founder of  Neoplatonism
 -  Tertullian, sometimes called father of Latin church
 -  Wang Pi,  Taoist
 -  M. Sattonius Iucundus, restorer of the  Thermae in  Heerlen
 -  Zhuge Liang, known as the greatest strategist during the period of the  Three Kingdoms
 -  Liu Bei, founding emperor of the  Kingdom of Shu
 -  Cao Cao, founding emperor of the  Kingdom of Wei
 
      
 Inventions, discoveries, introductions
      
       - A primitive form of glasses were developed for a nearsighted princess in Syria.
 -  Compass invented in China
 
      
 Decades and years
      
       
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        | Millennium | 
        Century | 
       
       
        |  4th BC: | 
         40th BC | 
         39th BC | 
         38th BC | 
         37th BC | 
         36th BC | 
         35th BC | 
         34th BC | 
         33rd BC | 
         32nd BC | 
         31st BC | 
       
       
        |  3rd BC: | 
         30th BC | 
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        |  2nd BC: | 
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        |  1st BC: | 
         10th BC | 
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         5th BC | 
         4th BC | 
         3rd BC | 
         2nd BC | 
        1st BC | 
       
       
        |  1st: | 
          1st | 
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          3rd | 
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        |  3rd: | 
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        |  4th: | 
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