The codex reached England as a diplomatic present. Cyril Lucaris, Greek Patriarch of Alexandria and afterwards of Constantinople, meant it for James I and sent it through Thomas Roe, the English ambassador to the Ottoman court. James died before it arrived, and it was presented to Charles I in 1627 instead. Lucaris said he had brought it from Alexandria, and the name it has carried ever since rests on that statement rather than on any independent record.
Its later custody is straightforward. It went into the Royal Library, and when George II gave that library to the newly founded British Museum in 1757 the codex went with it, as one of the foundation collections. It has stayed in London and is now in the British Library.
The date of its arrival is the fact most often repeated about it, and for a reason. The King James Bible had been finished in 1611. The translators worked from the printed Greek text available to them, which rested on late medieval manuscripts, and Alexandrinus, five centuries older than almost anything they had seen, landed in London sixteen years after they had put down their pens. It was the first of the great codices to be available to western scholarship, and the argument it began about how the New Testament text should be established has continued ever since.