Page from Jefferson's Farm Book showing Caractacus's lineage

Caractacus is probably Thomas Jefferson's most well-known riding horse.  Foaled on May 7, 1775, he was the offspring of Jefferson's mare Allycroker and Young Fearnought (owned by William Dandridge), a descendant of the Godolphin Arabian. 

Caractacus is the Latin form of Caratacus, a 1st-century C.E. chieftain of the British Catuvellauni tribe.  Caratacus led an armed resistance of the Roman invasion before finally being captured and sent to Rome as a prisoner.  According to the Roman historian Tacitus, Caratacus made such a stirring speech to the Roman Senate that he was pardoned and permitted to live the rest of his life in Rome as a free man.

[no date].  "Caractacus. his sire young Feamought who was got by old Fearn. on Calista. foaled May. 1775."^[1]

1775 May 7.  "Allycroker's colt by young Fearnought was foaled May 7."^[2]

1779 April 29.  "Recd. of Lively by T. Garth for his mare put a season to Caractacus £9-19."^[3]

[1781 May?]  (Isaac Granger Jefferson's recollections of the invasion of Richmond).  "When they fired the cannon Old master called out to John to fetch his horse Caractacus from the stable & rode off."^[4]

1782 April 15.  "Charge Wm. Turner a season to Caractacus."^[5]

1782 April 23.  "James Jones a season to Caractacus."^[6]

1782 May 9.  "Recd. of Jas. Jones 3/3 in full for season."^[7]

1782 May 16.  "Charge Colo. J. Harvie season of one mare to Caractacus.  Recd. order on him for 45/ from Bowl. Clarke.  Charge Dr. Gilmer season 3. mares."^[6]

1782 May 24.  "Charge Chas. Goodman a leap of Caractacus."^[6]

1784 March 2.  (Jefferson to John Key).  "Caractacus and grey horse as he pleases. Qu. if not better for John to go with Caract. if hired."^[10]

1790 February 22.  (Jefferson to Charles Lilburne Lewis).  "I send you the pedigree of Caractacus also the only two I have of the books your son desired."^[11]