 
 <prompt> Wetin be di last group wey dem mention? Based on di question wey dey before dis one, write something wey get di answer inside. E fit be 1 - 20 sentences. Context: <response>: The Roman Empire reach im greatest territorial extent during di 2nd century AD; di next two centuries see as Roman control dey reduce for dia outlying territories. Economic wahala, wey include inflation, and external pressure for di frontiers join body make di 3rd century dey politically unstable, with emperors wey dey throne dey change quick quick as new usurpers dey enter. Military expenses dey increase steadily during di 3rd century, mainly because of di war with Sassanid Persia, wey start again for di middle of di 3rd century. Di army double for size, and cavalry and smaller units replace di legion as di main tactical unit. Di need for money lead to increase for taxes and decrease for numbers of di curial, or landowning, class, and di number of dem wey dey ready to hold office for dia native towns dey reduce. More bureaucrats dey needed for di central administration to handle di needs of di army, wey lead to complain from civilians say dem get more tax-collectors for di empire pass tax-payers. 