Gregory IX, Pope (Ugolino), 135; anger at Frederick II, 136; letter on Frederick, 135-137; excommunicates Frederick, 137. Gregory X, Pope, describes Ghibellines, 176. Gregory XI, Pope, ends Babylonish Captivity, 217. Gregory XIII, Pope, 328, 329. Gregory XV, Pope, 345. Gregory XVI, Pope, 383. Grossi, Tommaso, 382. Guardi, 352. Guelfs, accept Henry VII, 156; trouble in Milan, 157; description of, 168, 169; fictitious revival of, 325. Guercino, 352. Guerrazzi, F. D., 382. Guicciardini, on condition of Italy, 253, 254; modern historian, 281. Guido Reni, 352, 360. Guilds, 164. Guinicelli, 184. Hapsburg, House of, 335, 338. Hawkwood, John, 213, 222. Haynau, 391. Henry IV, Emperor, 90; attempts to depose Gregory VII, 97; his letter to Gregory, 97-99; at Canossa, 99; death, 100. Henry VI, Emperor, his Sicilian marriage, 113; character, 114; his acts, 115. Henry VII, Emperor, 150; welcomed by Dante, 155, 156; enters Italy, 156; becomes Ghibelline chief, 157; receives letter from Dante, 157-159; death, 159; effect of, on fortunes of Can Grande and the Visconti, 198. Henry IV, King of France (Henry of Navarre), 337, 338, 357. Heresy, in Southern France, 123; in Italy, 125; in England and Bohemia, 220. Hildebrand, see Gregory VII, Pope. Hohenstaufens, 102, 113; their end, 143, 144. Holy Alliance, 370. Holy Roman Empire, beginning, 78; its extent, 79, 80; its power, 81; attitude toward Papacy, 84, 85, 89; concordat with Papacy, 100; death struggle with Papacy, 133; real end, 143; last flicker, 152-160; a shadow, 161; its petty bargainings, 217; extinguished by Napoleon, 365. Honorius, Pope, 133; crowns Frederick II, 135; death, 135. Humanists, 242, 244, 245. Humbert of the White Hand, 173. Humbert, King, 416. Hungarians, raids of, 77. Huss, John, 220, 221. Iconoclasm, 41, 42. Index Librorum Prohibitorum, 299. Innocent III, Pope, his education, 115; doings in Italy, 116; in Tuscany and Two Sicilies, 117; at Constantinople, 119; in Germany, 120; excommunicates Otto IV, 121; his doings in Europe, 122; in England, 122; Albigensian crusade, 123; triumph, 123, 124; recognizes St. Francis, 126, 127; referred to by Frederick II, 138; and Dominicans, 299. Innocent VIII, Pope, 286. Innocent X, Pope, 346. Innocent XI, Pope, 346. Inquisition, 298, 299. Investiture, lay, 86, 87, 89; settled between Empire and Papacy, 100. Italian language, 80; influenced by Dante, 184; its dialects, 185.