1862 — Magnus Goddard is born.
1864 — Young "Mag" is already a very active child, learning to run practically before he could walk. He has a tendency to want to climb things and loves to be outside, and frequently runs away from his nurses to get outdoors. He also is discovered to have a talent for hide and seek, much to her extreme vexation.
1865 — The child shows his first signs of magic, by bending a tree branch outside his window close enough for him to grab, and has almost managed to climb out the window before his nurse stops him.
1866 — At five years old, he is puzzled by the arrival of a sister, and is quite disappointed that he is not allowed to play with her.
1868 — A well-meaning governess tells the boy that he will be able to play with his younger sister, only if he promises to protect her a keep her safe. He takes this promise very much to heart.
1870 — Mrs. Lockhart dies moments before giving birth to another son, this one quite ugly at birth—at least, in Magnus' opinion, which is probably a bit biased. Mag resolves to despise the little gremlin who killed his mother, and avoids calling the baby by name until his death early the next year. His father's grief is alienating, and the two surviving children grow to rely on each other more as a result.
1873 - 1874 — Magnus goes off to Hogwarts. The hat momentarily debates whether to place him in Gryffindor or Hufflepuff. The boy has no opinions either way, but thinks that his father would be disappointed if he were a Hufflepuff—so he asks for that.
1874 - 1875 — Magnus, or rather "Lock," as he has begun to be called by his friends, discovers his intense fascination with Quidditch, and as soon as he is able, tries out for the team, though he is beaten out by older students. He participates in club Quidditch until he's able to make the team.
1875 - 1876 — Lock becomes a beater for the Hufflepuff team and finds Quidditch much more interesting than his studies, though he does passably well with his classes anyway. He adds Earth Magic, Muggle Studies, and Care of Magical Creatures to his class list.
1877 - 1878 — Lock is a bit bitter about having to move to Hogsmeade, since it means it will be more difficult to avoid his father. On the other hand, it does put him much closer to his friends, so he decides to look on the bright side and spends as much time as he can with friends, or out and about the town (more or less dragging the governess along). This is also the year that Fortuna joins him at Hogwarts. Lock does tolerably in his OWLs, but nothing impressive. He retains Earth Magic, Muggle Studies, Charms, Herbology, and Care of Magical Creatures.
1879 - 1880 — Lock graduates and is offered a position on the second-string of the Chudley Cannons, which he jumps at, much to his father's disappointment.
1881 — Lock is promoted to a first-string beater for the Chudley Cannons.
1883 — Lock's father marries in the Amortentia Tea Scandal of 1883. This does not please Lock, and to make a point he pretends to get married himself, to a friend (Ruth Grimstone). His father is not amused. Later that year Lock tries out for and joins the Quidditch World Cup team, though he's injured by a lightning strike in the first match and therefore misses out on much of the associated glory. He decides to quit Quidditch after the Cup so that he can get a more respectable job and provide for his new wife (surprise!) Ruth.
1884 — Ruth and Lock produce a child! Isn't that terrifying? They name her Margaery.
1885 — Oh my god another one! This one is named Calvin and has the other kind of gender marking. Fortuna also graduates this year, and seems to be much more inclined to make their father proud as she starts in on The Debutante Thing(™).
1886 — After an accident leaves a space open on the Cannons' roster, Lock quits his boring referee job and goes back to playing pro Quidditch. Which is great, because he hated being a referee literally every second of it, and it isn’t actually earning him any more money than Quidditch; the upward mobility that he thought would be present in the Ministry simply hasn’t materialized. His father is displeased.
1887 — Ruth announces that she is expecting, but after a holiday at the Sandition resort takes a terrible turn, loses the baby. Margaery, who nearly drowned, spends the next several weeks battling recurring pneumonia. The Lockharts grieve privately, and Lock continues to play for the Cannons.
1888 — The Cannons lose the Quidditch Cup to Puddlemere, mostly because Declan Wood is an idiot. Lock may or may not be holding a grudge.