Owen Lars became the stepbrother to Anakin Skywalker after his father, Cliegg, married Shmi Skywalker. When Obi-Wan contacts Owen in 19 BBY with the task of taking care of Anakin’s infant son, Luke, it is revealed that Cliegg had since passed away and Owen married his girlfriend Beru.
In 0 BBY (Episode IV), Owen and Luke purchased the droid R2-D2, who, unbeknownst to them, contained stolen plans for the Imperial superweapon, the Death Star. Stormtroopers tracked the droid to the Lars’ homestead where they interrogated Owen and Beru about the whereabouts of the droid before burning them both alive while Luke was away visiting with Obi-Wan Kenobi.