It is thought that Macklin was born near Culdaff, a village in Inishowen in the north of County Donegal in the province of Ulster, Ireland, in 1690, and moved to Great Britain in either 1725 or 1726; the dates in his early life are not entirely clear.

Even the necessity of business sometimes dissolved; however, after some contract and pay disagreements in the 1741–42 season, Macklin and nearly the entire Drury Lane resident company left and attempted to find work elsewhere.

[2] For several decades, the popular version of the play was a "fixed" text by George Granville, titled The Jew of Venice.

[2] In seeking to portray Jews exactly how they looked, Macklin emphasised the notion of historical accuracy in costuming, which would later become an inherent feature of realism in the 19th century.

This faithfulness to Shakespeare's original intent for the character, combined with Macklin's revolutionary method of attempting some semblance of realism in his performance, resulted in uproarious applause.

Macklin himself confesses, "On my return to the green-room, after the play was over, it was crowded with nobility and critics, who all complimented me in the warmest and most unbounded manner".

He was the creator of Sir Pertinax Macsycophant, a famous burlesque character, and he was Macbeth at Covent Garden in 1772, in a production with authentic Scottish costumes.

As a challenge, Samuel Foote allegedly wrote The Great Panjandrum, a nonsense poem designed to be particularly difficult to memorise.

[5] Macklin returned to the stage, but finally retired in 1789, when he found he was no longer able to recall the entire part of Shylock.

[citation needed] He wrote many plays, including Love a la Mode (1759),[2] The School for Husbands, or The Married Libertine (1761), and The Man of the World (1781).

The True-Born Irishman (1763), renamed The Irish Fine Lady for its English production, was a hit in Ireland, but a flop in England.

[2] According to Wilson Goldfarb, "the predominant approach to acting in the 18th century is usually described as bombastic or declamatory, terms that suggest its emphasis on oratorical skills".

[9] Due to this emphasis on speaking, rehearsal time was short, stage movement was standardised, and actors often spoke directly to the audience rather than characters onstage.

He stressed the importance of a thorough knowledge of one's role, of propriety of dress, and of attention the business of the scene; the necessity of avoiding monotony of tone".

[citation needed] Most importantly, Macklin wanted his students to speak as they would in everyday life; basically transferring reality to the stage.

[citation needed] To cope with projection in the theatres, Macklin would often recite from Milton's Paradise Lost or soliloquies from Macbeth or Othello, having his students to imitate him in clarity, speech, and volume.

[10] Appleton adds that "while he concentrated primarily on achieving clear and natural diction, he stressed as well the importance of mastering variety of tone and pause to indicate transitions of thought and associations of ideas".

Appleton states that "actors, compelled by the repertory system to know scores of parts, generally relied on conventional attitudes, gestures, and tones to carry them through a performance and felt little enthusiasm for this discipline.

For the rest of his life, Macklin would continue to train his students with such intensity and passion and through them, make an important contribution to the English Theatre.

The incident occurred in the Scene Room of the Theatre Royal, Drury Lane, in front of many witnesses, and Macklin, after the sudden fit of temper, was sorry and arranged for a physician to attend to Hallam.

The punishment for manslaughter was the branding of a letter 'M' upon the hand, by this period not with a hot but with a cold iron, although there is no evidence that this was actually carried out on Macklin.

While his second wife gave his birth year as 1690 on the memorial tablet installed in St. Paul's Church, Covent Garden, making him 107 at his death; others have suggested that he was born in 1699 or 1710.

His memorial shows a dagger piercing the eye of a theatrical mask, a contrite reference to his altercation with Thomas Hallam.

[citation needed] Macklin's famous role as Shylock and introduction of naturalistic acting would later influence realism in the 19th century.