In this article, Rogers surveys a broad range of historical treatment of hair. He discusses the taxation of beards in both England and Russia, noting that the English laws on taxing hair fell out of fashion and were ultimately deemed "too absurd to be enforced."
Offenses against others' hair could be the basis for civil liability. Rogers writes:
In Ireland, by the Brehon law, a heavy fine had to be paid by any one who maliciously shaved the false locks of a poet or of a scholar, or of a show girl, or who cut off the eye lashes, or the hair of the brow, or the beard or whiskers of a man.
Robbing a man of his beard, among the Saxons, according to Alfred's laws, was punishable by a fine of twenty shillings; he who shaved a priest against his will was mulcted in thirty shillings; while binding the ecclesiastic, as well as shaving him, raised the penalty to two pounds.
Rogers doesn't stop there. He goes on to summarize the importance of horses' hair, noting that the cutting of a horse's mane or tail would require compensation as well as the provision of a substitute animal while the injured horse was kept in hiding. The church took mixed positions on the length of women's hair, with some members of the clergy encouraging the cutting of hair as a symbol of chastity, and others criticizing Joan of Arc's choice to wear short hair as blasphemy.
Rogers concludes with an anecdote about Lord Mansfield:
Lord Mansfield tried a man for assault, he was convicted; the Court thought imprisonment an unsuitable punishment under the circumstances; an affidavit was produced in which the offender stated he was wholly unable to pay a pecuniary fine. While this was being read the man stood proudly erect, his face adorned with enormous whiskers and moustaches, the pride of his heart, his boast in his cups. Mr. Dunning, for the prosecution, suggested to the judge that "as the prisoner had very fine moustachios and whiskers, perhaps his lordship would take the punishment out of these, and order him at once to be shaved."
For a modern perspective on a different, hair-related legal issue, I would recommend Paul C. Giannelli's, Microscopic Hair Comparisons: A Cautionary Tale, 46 Crim. L. Bull. 7 (2010). From the abstract:
This article examines the judicial history of microscopic hair analysis, including its role in several wrongful convictions. It discusses the misuse and the abuse of hair evidence, and the failure to establish an empirical basis for the technique. In sum, hair evidence provides a cautionary tale for other forensic techniques.