The text of this edition is based on Dyce's modernised text of 1861 compared with the later collations of Grosart and Collins, and editions of single plays by Ward, Manly and Gayley. The editor has been conservative in accepting modifications of Dyce's text. The act and scene divisions as found in Collins have been adopted, and the location of scenes has been indicated throughout.
The first extant edition of _Alphonsus, King of Arragon_, was printed in quarto by Thomas Creede in 1599. Lowndes mentions a quarto of 1597 of which no trace can be found. Of the two copies of the quarto of 1599 now known, one is in the library of the Duke of Devonshire, and the other is in the Dyce Library at South Kensington. _Alphonsus_ is not mentioned by Henslowe in his _Diary_, nor is there any record of the play in the Stationers' Registers. Nothing certain can be said concerning the circumstances and dates of composition and first performance of Greene's plays. But there can be no doubt that this is one of Greene's earliest plays, for in the Prologue Greene says through the mouth of Venus:
"And this my hand, which usèd for to pen The praise of love and Cupid's peerless power, Will now begin to treat of bloody Mars."
Nor can there be any doubt that the play was written in imitation of Marlowe's _Tamburlaine_, mention of which occurs in IV. 3. A second part, "when I come to finish up his life," is promised in the Epilogue. That the second part was not written is probably an indication of the failure of the piece. In the Preface to Greene's _Perimedes_ of 29th March 1588, we learn that two "gentlemen poets" had caused two actors to mock Greene's motto, _Omne tulit punctum_, because his verse fell short of the bombast and blasphemy of Marlowe's early style. It has been suggested that it may have been the verse of _Alphonsus_ that was ridiculed. Certainly it must have been this play, or a lost early play, for it was in drama that the "mighty line" appeared. There is in Peele's _Farewell_, April 1589, a reference to a piece of mechanism occurring in this play which closely connects it with Marlowe's first play, "Mahomet's Poo and mighty Tamburlaine." This has been discussed in the General Introduction. Greene's play is based distantly on the history of Alphonso I. of Naples and V. of Arragon (1385-1454), though with no pretence to historical accuracy.