Robinson's quick return after quitting 'weakened Paisley'
Peter Robinson's swift return after resigning as deputy leader of the DUP was seen as marking a shift at the top of the party.
Mr Robinson quit in 1987 amid rows over the way forward for unionism. When he returned two months later, he was seen as "a force to be reckoned with".
A political developments report from January 1988 assessing the fallout concluded Mr Paisley had been weakened.
"Although Robinson's return has probably involved a degree of compromise on both his and Paisley's side, it is inevitable that the greater retreat is being seen as that of the party leader," it read.
"The political gamble which led Robinson to resign appears to have paid off handsomely, and his re-appointment as Paisley's deputy and his membership of the new unionist panel must mean that he is back as a force to be reckoned with."