Who is Herbert? When did Pip meet him before? How is he related to Miss Havisham and to Pip's tutor?

It is in Chapter 21 that Pip, now a man with expectations, meets Herbert Pocket again. He realises that Herbert was the young boy that he fought in Satis House in Chapter 11. Herbert Pocket is now grown up and though witout prospects and poor, he is clearly a gentleman and beings instructing Pip in the manners of a gentleman in Chapter 22 very sensitively. Jaggers has organised for Pip to stay with Herbert, and it is to be Herbert's father, Matthew Pocket, who will be entrusted with Pip's education to transform him into a gentleman. It is Matthew Pocket who is related to Miss Havisham and this explains Herbet's presence at Satis House in Chapter 11.