According to Effie Bowie, he was a London merchant who immigrated to Prince George's Co., and came to Maryland before 1669.
Skordas gives two Richard Lancasters as early immigrants: one was transported in 1669, the other in 1673.
According to Digges and Poutney, he was listed as a “merchant” in London in 1707, and was in PG County by 1712 when he witnessed a will. They say he was said to have married twice in England, and had his children by his second wife. [2, 3, 4]