Paul was the first but illegitimate son of Sir Joseph de Brechin, a fact that blighted him for the rest of his life.  At the age of five his father had a second son born in wedlock and therefore entitled to claim the de Brechin title and lands.  Although the boys were brought up together Sir Joseph was aware of the animosity between then, especially Paul.

Sir Joseph looked for a suitable tutor for Paul, someone who would be able to quell his anger and he found one in the form of an old acquaintance of his - Elizabeth Beckett.  Although Elizabeth schooled him well, it was after a heated argument with Elizabeth's husband - Mike that Paul was cast out of the family and onto the streets to fend for himself.

It was a few years later when Paul, by chance, met the second Earl of Buchan - John Comyn the Black that he learned of his father's death and of the change of allegiance to Robert the Bruce away from Balliol that the new Lord of Brechin - Sir Harry had taken. The Earl of Buchan regarded this as traitorous and promised Paul that if the worked for him and after the demise of Bruce and his supporters, that he would receive a knighthood and be able to claim the lands of Brechin.  Paul instantly agreed to this and found himself in a position of power and wealth and able to now exert his influence on those around him.  He proved to be extremely cunning and concocted a plan to betray his brother by blackmailing one of his men - David de Brownhill.  However, the plot was revealed by the powers of the church and Paul was captured by church agents and awaited trail for treason. Paul with the help of the Earl of Buchan managed to escape, the Earl decide to send Paul to England for his own protection , this was not a problem for Paul as he had dealings with the English in the past, it was Paul who had advised Gaveston of Henry Fennes dealings with Sir Harry.  Paul now worked directly for the English court, first helping to influence English/French relations; this would then allow England to concentrate on crushing Robert the Bruce once and for all. Before Bannockburn Paul was sent ahead to use his knowledge and experience to undermine Bruce's Scottish factions. Sir Andreas of Thurso had been sent to patrol the borders in front of an expected English advance. He has received word of Paul's movements and confronted him at Selkirk there Paul feigned surrender and cruelly cut down two of Sir Andreas's men before escaping.

Paul had received word that many a Scottish Magnate loyal to Bruce had placed their womenfolk into the protection of Kildrummy castle.   Paul in a last act of desperation attempted to raid the castle and take the ladies prisoner to use as hostages in the name of his paymaster - the Earl of Buchan. Using his guile he tricked his way into he castles service entrance only to be met by Alan of Harris who had been placed at Kildrummy by Sir Harry to protect the women. During the struggle Alan was badly injured but managed to raise the alarm for help, Paul disappeared.  After Bannockburn nothing more was heard of Paul, some say the Earl of Buchan full of rage at Paul's failure had him killed, others say that he had fled to Europe still plotting to one day return to seek revenge on all of his enemies.