Supporters: two Friars Minor, haired, bearded and vested, each holding a raised sword, standing on a ribbon with the motto: DEO JUVANTE.
The Rock of Monaco had been a coveted possession from the beginning and was named Monoïkos by the Greeks.
The House of Guelph was originally an Italian noble family which branched off to become, amongst others, the House of Welf in Germany, specifically Bavaria and Hanover.
Dressed as a Franciscan friar (or Friar Minor), Francesco was at first greeted at the gates of Monaco's castle, but then seized the castle with his cousin Rainier I, Lord of Cagnes, and a group of men behind him. The event is commemorated by choosing two friars armed with swords as the Supporters. Francesco held the citadel of Monaco for four years before being chased out by the Genoese. The battle was taken over by his kinsmen. Francesco thus failed to establish Grimaldi's rule over Monaco, but was the first to attempt to do so.
Francesco died childless, but after his death, in 1309, he was succeeded by his cousin (and now stepson) Rainier I whose family still rule Monaco today. The Grimaldis purchased Monaco from the crown of Aragon in 1419 and became the official and undisputed rulers of "the Rock".