Definition of "perforce"

If ſhe denie, Lord Hastings goe with him,And from her iealous Armes pluck him perforce.

c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene i]

For you, most wicked sir, whom to call brotherWould even infect my mouth, I do forgiveThy rankest fault; all of them; and requireMy dukedom of thee, which, perforce, I knowThou must restore.

1610–1611 (date written), William Shakespeare, “The Tempest”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act V, scene i]

Mr. Wickham's happiness and her own were perforce delayed a little longer, and Mr. Collins's proposal accepted with as good a grace as she could..

1813 January 27, [Jane Austen], chapter 17, in Pride and Prejudice: […], volumes (please specify |volume=I to III), London: […] [George Sidney] for T[homas] Egerton, […]

"Keep fast thy hold, for by such stairs as these,"The Master said, panting as one fatigued,"Must we perforce depart from so much evil."

1882, Henry Wadsworth Longfellow, Inferno, canto 34

So, bevelling around by Mullett's and the Signal House which they shortly reached, they proceeded perforce in the direction of Amiens street railway terminus

1922 February, James Joyce, “[Episode 16]”, in Ulysses, Paris: Shakespeare and Company, […]

Accordingly work perforce had to be begun. The first sod was cut at Anley, near Settle, in November, 1869, [...].

1939 July, John D. Hewitt, “Some Notable British Main Lines: 1. Settle and Carlisle, L.M.S.R.”, in Railway Magazine, page 35

Adult immigrants must perforce learn some English, and their children are likely to become English monolinguals.

2006, Alejandro Portes, Rubén G. Rumbaut, Immigrant America: A Portrait, 3rd edition, page 239

The central issue in this case is whether the procedures followed respected the applicants’ family life or constituted an interference with the exercise of the right to respect for family life which could not be justified as necessary in a democratic society. […] It is true that Article 8 contains no explicit procedural requirements, but this is not conclusive of the matter. The relevant considerations to be weighed by a local authority in reaching decisions on children in its care must perforce include the views and interests of the natural parents.

2013 January 8, European Court of Human Rights, A.K. and L. v. Croatia‎, number 37956/11, marginal 62–63