It is narrated from al-Sha'bi (may Allah have mercy on him) that Sayyiduna Umar and Sayyiduna Ali (may Allah be pleased with them both), and Shurayh and Masruq (may Allah have mercy on them both) said: There is no marriage without a guardian.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13642