After the end of the Trojan War (1260-1150 BC), the Dorians invaded the Greek mainland and Greek industry collapsed. Iron, although not as sturdy as bronze, came into wide use because of its cheapness. The Greeks migrated to the western coast of Turkey (Ionia) and engaged in profitable commerce. A new class was created in which the common people rose to a social status previously occupied by aristocrats. Fighting techniques shifted from royal cavalry to hoplite (armored infantry) conflict. This led to equality in warfare, since there were no advantages to the wealthy who could afford to keep the best horses. At the end of this period, the position of kingship was eliminated and the role of the family as the center of political power decreased. This led to a revolution in the concept of law and order. The new forms of justice involved codifying laws in writing and electing impartial magistrates ("kosmoi"). Political and social power shifted from rule by force to one by language, speech, and writing. The open debate that accompanied this change was transferred to the description of nature, and led to the development of rational thought without the inclusion of supernatural explanations.