We do not know when Diego Gelmirez was born. We don't even know where. But it was quite likely at the Torres del Oeste, the formidable fortress towers administered by his father, Gelmirio, in the service of Bishop Diego Pelaez whom we have already met. His date of birth was also most likely sometime during the 1060's.
Diego's father was greatly trusted by Diego Pelaez. The geographical area he governed on the River Ulla was particularly important strategically being vulnerable to periodic Viking and Norman raids.(During July every year there is a re-enactment of one of these at the site of the Torres which still exist.) Gelmirio, though likely of no great social rank, was considered by all as a "rising man" and young Diego most likely witnessed many comings and goings of the high and the mightly. Perhaps this fuelled his young ambition to rise higher than his father.
Diego attended the Cathedral school at Compostela and it seems he was destined for an ecclesiastical career from very early on. After his schooling, in which he was given a good grounding in church matters, the scriptures, and the law, he spent some time at the royal court, most likely during his late teens. Here, travelling with the royal retinue, young Diego had the perfect chance to watch, listen, and learn and to ingratiate himself into the company of those who may at some point be able to give him a leg up the ladder of preferment.
Sometime before 1085, Diego Gelmirez was back in the household of Bishop Diego Pelaez where we can be sure his listening skills were put to great advantage. What he did with what he learned one can only guess.
What is clear, however, is that Diego survived his patron's downfall and disgracein 1087. Perhaps he saw his career at stake and fought hard to secure it. Maybe as Fletcher suggests, he "...may not have been able to keep his hands clean". Diego, as you will learn, had a habit of coming up smelling of roses no matter what he did. Certainly his extreme reluctance in later years not to travel through the Kingdom of Aragon where Diego Pelaez was living in exile certainly makes us wonder if Diego Gelmirez had a guilty conscience...?