The historian William Henry Scott theorizes that this may have been Ferdinand Magellan's fatal error. Magellan assumed that Rajah Humabon was the king of the land and thus of Mactan as well. But the island of Mactan, the domain of Lapu-Lapu and another "datu" named Zula, was in a location that enabled them to intercept trade ships entering the harbor of Cebu, Humabon's domain. Thus it was more likely that Lapu-Lapu was actually more powerful than Humabon. Humabon himself was married to Lapu-Lapu's niece. When Magellan demanded that Lapu-Lapu submit as his "king" Humabon had done, Lapu-Lapu purportedly replied that "he was unwilling to come and do reverence to one whom he had been commanding for so long a time".