Correspondents Interlocutors, Mentors and Dramatis Personae 

Charles Babbage (1791-1871)
Mathematician, scientist and inventor of the Analytical  Engine
Mentor, collaborator and correspondent
That Enchantress who has thrown her magical spell around the most abstract of Sciences and has grasped it with a force which few masculine intellects (in our country at least) could have exerted over it.
CB to MF (Ada Lovelace, 86)
Lord Byron (1788-1824)
Romantic poet, Ada's father
Is thy face like thy mother's, my fair child!Ada! sole daughter of my house and heart?When last I saw thy young blue eyes, they smiled,And then we parted,- not as now we part,But with a hope.
Anne Isabella ('Annabella) Noel Byron (1792-1860)
Educational Reformer, Ada's mother and teacher
'Arithmetic, the first part o Algebra & Paisley's Practical Geometry'. Present information on these subjects confined to some general ideas of the value of numbers, without facility in working them
LB to DrK [B/LB/71, fol.153r]
Augustus de Morgan (1806-1871)
Mathematician, logician and first Professor of Mathematics at University College LondonTutor and correspondent
I am afraid you will indeed say that the office of my Mathematical Counsellor or Prime Minister is no joke.
AL to AdM [B/LB/170, fol.35r]
William Frend (1757-1841)
Mathematician, non-conformist, social reformer, writer and Ada's early tutor
I am very much interested on the subject just now, but I cannot make out things at all, viz: why a rainbow always appears to the spectator to be an arc of a circle.
AL to WF, 15-3-1834 [B/LB/171, fols 127r-127v]
William King - Noel (1805-1893)
Landowner with an interest in agricultural economics, Ada's husband
What a happiness it is to feel towards any one what I do towards you, & to feel that it is reciprocal- I do not think there can be any earthly pleasure to that of reposing perfect truct & confidence in another, more, especially when that other is to become one's husband. AL to WK, 28 June 1835 (in Ada, 57)]
Dr William King (1786-1865)
Physician, philanthropist, Lady Byron's friend  and Ada's early tutor
getting on very well so far, with Euclid. I usually do four propositions a day, and go over some of the old ones. I expect now to finish the 1st book in less than a week.
AL to WK [B/LB/172, fol132r]
Mary Somerville  (1780-1872)
Mathematician, scientist, mentor and correspondent
I am very much delighted to have a cap made by you and the more so as it shows that we mathematicians can do other things besides studying xes and ys
MS to AL [B/LB/174, fol.19r]