The Dufourspitze is the highest peak of Monte Rosa, an ice-covered mountain massif in the Alps. Dufourspitze is the highest mountain peak of both Switzerland and the Pennine Alps and is also the second-highest mountain of the Alps and Western Europe, after Mont Blanc. It is located between Switzerland (Canton of Valais) and Italy (Piedmont and Aosta Valley). The peak itself is located wholly in Switzerland. Following a long series of attempts beginning in the early nineteenth century, Monte Rosa's summit, then still called Höchste Spitze (), was first reached on 1 August, the Swiss National celebration day, in 1855 from Zermatt by a party of eight climbers led by three guides: Matthäus and Johannes Zumtaugwald, Ulrich Lauener, Christopher and James Smyth, Charles Hudson, John Birkbeck and Edward Stephenson. Naming The peak is distinguished by the name Dufourspitze (in German, lit. Dufour Peak; , ). This replaced the former name Höchste Spitze () that was indicated on the Swiss maps before the Federal Council, on January 28, 1863, decided to rename the mountain in honor of Guillaume-Henri Dufour. Dufour was a Swiss engineer, topographer, co-founder of the Red Cross and army general who led the Sonderbund campaign. This decision followed the completion of the Dufour Map, a series of military topographical maps created under the command of Dufour. The point just east of the Dufourspitze and only 2 metres lower, the Dunantspitze, was renamed in 2014 in honor of Henry Dunant, the main founder of the Red Cross. Elevation The Dufourspitze of Monte Rosa is the most elevated point of Valais and Switzerland, although it is not the most prominent of the country, that distinction belonging to the Finsteraarhorn, nor the most isolated, that distinction belonging to Piz Bernina. The Swiss national map gives an elevation of for the summit, which is 4,441 metres above Lake Maggiore, Switzerland's lowest point. The height difference between the summit and the plains of northern Italy, from where Monte Rosa is well visible, reaches over . Monte Rosa has a topographic prominence of , the Great St Bernard Pass being the lowest col between it and the culminating point of the Alps. A 2000 survey, involving universities and the offices of cartography of Italy and Switzerland and part of the TOWER project (Top of the World Elevations Remeasurement), was made in order to record a more precise elevation for Monte Rosa. The result was