DUP leader's ill-health dates back to May
Peter Robinson suffered a heart attack in May and in the intervening months has appeared under strain at times amid the intense political pressure of issues ranging from welfare reform to the Kevin McGuigan murder.
The 66-year-old received treatment immediately after falling ill on the morning of Monday May 25, on the eve of the crucial welfare debate in the assembly.
He was taken to the Ulster Hospital, close to his home in the Castlereagh hills, and transferred by ambulance to the specialist cardiac unit at Belfast's Royal Victoria Hospital where he had stents inserted.
The DUP leader left the cardiac unit four days after he fell ill and was fulsome in his praise of medical staff for their "tremendous work".
It was the second time he had spent time away from his desk, the previous occasion being in early 2010 when he stepped aside as first minister in the wake of the scandal engulfing his wife Iris and her teenage lover Kirk McCambley.
The rules governing the assembly allow an interim leader to take over temporarily and then - as now amid the current crisis over the McGuigan murder - he was replaced by Arlene Foster.
Doctors allowed the DUP leader to recuperate at home and he was back to work on June 2 attending talks including a meeting hosted by the British and Irish governments to tackle the stand-off over welfare reform.
He announced shortly afterwards that his lifestyle and an unhealthy diet of fast food had been responsible for his heart condition.
Mr Robinson had said he would cut back on his work as he recuperated from his illness.
However, reports yesterday suggested he has admitted at times struggling with his health while working, including feeling in poor physical condition during one Executive meeting due to his mixture of medication.