The subject of ‘arriving’

The passage below is from A History of the Index by Dennis Duncan.

And so we come, at last, to the entrance of our main players, Robert and Hugh. Grosseteste’s origins are both humble and obscure. He was born in Suffolk, some time around 1175, probably into a family of tenant farmers. It was a lowly start that would be held against him even after a lifetime of service and achievement – as Bishop of Lincoln, his underlings would openly grumble that someone of such mean beginnings had been appointed above them. But the details of Grosseteste’s background –so consequential to his peers – have been lost to us now. It is not even clear whether Grosseteste was the family name or an epithet applied once Robert’s abilities had become manifest. Grosse tête: big head. In the seventeenth century, the Church historian Thomas Fuller would claim that Grosseteste ‘got his surname from the greatness of his head, having large stowage to receive, and store of brains to fill it’. Whatever, Robert’s capacious intellect was recognized early on. Having acquired some schooling, perhaps supported by a local nobleman, the young Robert would find himself in the service of the Bishop of Hereford, arriving with a letter of recommendation from the historian Gerald of Wales:

I know he will be a great support to you in various kinds of business and legal decisions, and in providing cures to restore and preserve your health, for he has reliable skill in both these branches of learning, which in these days are most highly rewarded. Besides, he has a solid foundation of the liberal arts and wide reading, which he adorns with the highest standards of conduct.

I cannot figure out ‘who’ arrived with a letter of recommendation.

Whether it is ‘the young Robert’ or ‘the Bishop of Hereford’ I cannot decide.

In the light of common sense it seems reasonable that it is Robert, since usually someone who want a job visits a prospect employer with a letter of recommendation.

But since ‘arriving’ is located just after ‘the Bishop of Hereford’ I cannot rule out the possibility of it being the Bishop.

Thanks in advance.