A Jew of Frankfurt is mentioned in connection with the sale of a house at Cologne between 1175 and 1191. Eliezer ben Nathan, rabbi at Mainz toward the end of the twelfth century, says that there were not then ten adult Jews in Frankfurt. The first reliable information concerning Frankfurt Jews dates from 1241, on May 24 of which year 180 Hebrews were killed during a riot and many fled, this being the first "Judenschlacht" or slaughter of the Jews. As the affair was detrimental to the income of the emperor, he was incensed with the city for seven years. King Conrad IV did not forgive the citizens until May 6, 1246. The emperor distributed the income he derived from the Jews so liberally among the princes and his retainers that he had little left for himself; yet the Jews remained under his protection. In 1286 King Rudolf pledged to Count Adolf of Nassau 20 marks yearly from the income derived from the Frankfurt Jews. When Adolf was made king under the title of "Adolf of Nassau", he pledged these 20 marks to the knight Gottfried of Merenberg (1292); and the latter again pledged 4 marks of this sum to the knight Heinrich of Sachsenhausen. King Adolf also gave 25 marks to Glottfried of Eppstein as a hereditary fief; and from 1297 he gave 300 marks yearly of the Jews' tax to the Archbishop of Mainz, adding to this sum 500 pounds of hellers in 1299. As early as 1303 the archbishop pledged 100 marks of this amount, and thus the Jews of the city of Frankfurt became subject to the archbishop. The emperor, however, attempted to exact still more money from the Jews, and it was only thanks to the resistance of the city that King Adolf did not succeed in 1292 in extracting from them the sum required for his coronation.