I have followed all these matters carefully from their sources. I thought it was good to record it in order for you, your Excellency Theophilus.
Luke spent a period of time in Palestine (Injil, Acts 21:8-27:1). It seems he spent much of the time researching with eyewitnesses who had seen Isa.
Some people think this is a title, meaning "person who loves Allah", rather than a name. He may have been the lawyer for Paul (see also the Injil, Acts 1:1)